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The Automobile 
Handbook 


A Manual of Practical Information 
for Automobile Owners, Repair 
Men and Schools 


L 


A i! >- 

Elliott $rookes 


Revised and Enlarged By 

HAROLD P. MANLY 

Author of “Automobile Starting and 
Lighting.” 


Subjects Arranged in Alphabetical Order and 
Indexed 


FULLY ILLUSTRATED 


CHICAGO 

FREDERICK J. DRAKE & CO. 
Publishers 















Copyright 1921, 1919, 1918 , 1916 , 1913 , 
1910, 1907 and 1906 

By FREDERICK J. DRAKE & CO., 
CHICAGO. 

— 


^ / 



g>CL A608173 



JAN 27 192! 






“MM3 


PREFACE 


c< 



The Automobile Handbook has been designed 
to afford all those interested in self-propelled 
vehicles a concise, complete and accurate work 
of reference from which may be secured, in 
the shortest possible time, anything from a 
single fact to a'complete exposition of the major 
subjects pertaining to the motor car. 

The subject matter of the Handbook has been 
arranged in alphabetical order with a careful 
classification and grouping under their main 
titles of such important subjects as Ignition, 
Starting and Lighting, Engines, Carburetors, 
Fuels, Axles, Valves and others of equal value. 

Detailed treatment has been included on all 
subjects necessary to fully cover the automobile 
field, and sufficient information and description 
have been given to make the treatment of each 
subject complete, either from the standpoint of 
the operator or repairman. 

It will be noted that all details have been 
treated in accordance with present day usage 
and that all of the important principles and 
types of construction of recent adoption have 
been covered. The underlying principles of 
operation, of course, remain unaltered, but their 
application has changed radically in a great 
many cases. It is for this reason that descrip- 
5 


6 


The Automobile Handbook 


tions of methods of building which may be con¬ 
sidered obsolete are omitted from the book, thus 
avoiding possible confusion as well as loss of 
time in useless study. 

The reader’s attention is called to the index, / 
which is complete and lists all subjects under 
any of the names that might come to mind and 
which also gives a complete outline of the cross 
references and related subjects which are re¬ 
quired to continue an investigation along any 
line selected. 

H. P. Manly. 

Chicago, March 1, 1919. 


The Automobile Handbook 


Acid, Battery. The liquid electrolyte of the 
lead-acid type of storage battery is composed of 
varying proportions of sulphuric acid and wa¬ 
ter. The sulphuric acid must be chemically pure 
and the water must be distilled or at least must 
not contain foreign matter. The proportion of 
acid is measured by the specific gravity of the 
mixture. 


TABLE 1 

Percentage of Acid Number of Parts of Acid to 
Specific in Mixture Each 100 Parts of Water 

Gravity By By By By 

of Liquid Volume Weight Volume Weight 


1.100 

9.0 

15.0 

10 

17% 

1.125 

11.0 

18.5 

12% 

22% 

1.150 

13.4 

22.0 

15% 

28 

1.175 

15.7 

25.4 

18% 

34 

1.200 

18.1 

28.5 

22 

40 

1.225 

20.5 

32.5 

25% 

48% 

1.250 

23.0 

35.5 

29% 

55 

1.275 

25.5 

38.5 

34 

62% 

1.300 

28.0 

42.0 

39 

72% 


The proportions when measured by weight are 
always greater than by volume because the acid 
is nearly twice as heavy as water. See Battery, 
Storage . 

Accelerator. The name given to a foot control 
for the carburetor throttle valve. 

Accumulator. An old and now little used 



8 The Automobile Handbook 

name for a storage battery. See Battery, Stor¬ 
age. 

Air. Air consists, by weight, of oxygen 77 
parts and nitrogen 23 parts; by volume, of 21 
parts oxygen and 79 parts nitrogen. One pound 
of air at atmospheric pressure, and 70 degrees, 
Fahr., occupies 13.34 cubic feet of space. One 
cubic foot of air weighs 1 1-7 ounces. 

Air Resistance, Horsepower Required to 

Overcome. The power required to move a plane 
surface, such as the vertical projection of an 
automobile, against the air, does not become of 
much importance until the car attains a speed 
of 10 to 12 miles per hour, when it becomes an 
important factor. 

The horsepower required to propel an auto¬ 
mobile against the resistance of the air may be 
approximately calculated by the following for¬ 
mula. Let Y be the velocity of the car in feet 
per second, and A the projected area of the 
front of the car in scyiare feet—this may be as¬ 
sumed as the height from the frame to the top 
of the body multiplied by the width of the seat 
at the floor line of the car—let H.P. be the 
horsepower required to overcome the air re¬ 
sistance, then 

V 3 X A 

H.P.=- 

240,000 

To simplify the use of the above formula, 
Table 2 gives sneeds in miles per hour corre- 



The Automobile Handbook 


9 


sponding to their respective velocities in feet 
per second and also cubes of velocities in feet 
per second. 


table 2. 

CUBES OF VELOCITIES IN FEET PER SECOND. 


Miles per 
Hour of 
Car. 

Feet per 
Second 

Cube of 
"V elocity 
in Ft. per 
Second. 

Miles per 
Hour of 
Car. 

Feet per 
Second, 

Cube of 
Velocity 
in Ft. per 
Second, 

10.2 

15 

3,375 

34.0 

50 

125,000 

13.6 

20 

8,000 

40.9 

60 

216,000 

17.2 

25 

15,625 

47.7 

70 

343,000 

20.4 

30 

27.000 

54.4 

80 

512,000 

27.2 

40 

64,000 

61.3 | 

90 

729,000 


To ascertain approximately the horsepower 
that will be necessary to drive a car against a 
wind of known velocity, the speed of the cal 
must be added to that of the wind, and the re¬ 
quired horsepower may be found either by use 
of the formula given or by reference to Table 
3, which gives the horsepower per square foot 
of projected surface required to propel a car 
against the resistance of the air, with varying 
speeds in miles per hour or velocities in feet 
per minute. 

table 3. 

HORSEPOWER REQUIRED PER SQUARE FOOT OF SURFACE, TO MOVE 
A CAR AGAINST AIR RESISTANCE. 


Miles per 
Hour of 
Car. 

Feet per 
Second. 

Horse¬ 
power per 
Square 
Foot of 
Surface. 


Miles per 
Hour of 
Car. 

Feet per 
Second. 

Horse¬ 
power per 
Square 
Foot of 
Surface. 

10 

14.7 

0.013 


40 

58.7 

0.84 

15 

22.0 

0.44 


50 

73.3 

1.64 

20 

24.6 1 

0.105 


60 

87.9 

2.83 

25 : 

36.7 I 

0.205 


80 

117.3 

6.72 

30 1 

44.0 1 

0.354 


100 

146.6 

13.12 


The horsepower given by the formula and 
Table 3 simply refers to the additional power 





















10 


The Automobile Handbook 


necessary to overcome air resistance and not to 
the actual power required to propel a car at a 
given speed; this is entirely another matter. 

Alcohol. There are two kinds of alcohol: 
methyl, or wood, alcohol, CH 4 0, and ethyl, or 
grain, alcohol, C 2 H 6 0. The former has been 
found objectionable for use in internal-combus¬ 
tion engines, because it apparently liberates 
acetic acid, which corrodes the cylinders and 
valves. 

As alcohol is a fixed product, and the same 
the world over, it has a great advantage as a 
motive power over gasoline and other petro¬ 
leum products. Denatured alcohol contains 
4,172 heat units per pound as compared to 
18,000 for gasoline, and, as its cost is higher, 
this fuel would not seem practicable from an 
economic standpoint. By mixing the alcohol, 
however, with a high grade of gasoline, its price 
is lowered, and the number of heat units per 
pound greatly increased. Mixtures containing 
50 per cent alcohol have a calorific power of 
11,086 heat units per pound, and as it has been 
found by numerous tests in France that it re¬ 
quires no more of this mixture than of gasoline 
to develop a certain power, its efficiency is con¬ 
siderably greater, reaching a value of 24 per 
cent as compared to 16 for the gasoline motor. 
In some recent experiments in France with a 
motor specially constructed for the use of alco¬ 
hol, the consumption was lowered to 0.124 pound 


The Automobile Handbook 


11 


per horse power, using 50 per cent carburetted 
alcohol. 

Grain, or ethyl, alcohol has a specific gravity 
of .795, and may be obtained by distillation 
from corn, wheat, and other grains, potatoes, 
molasses, or anything containing sugar or 
starch. When pure, it absorbs water rapidly 
from the air, more rapidly in fact than it loses 
its own substance by evaporation; but when 
diluted to the proportion of about 85 per cent, 
alcohol and 15 per cent, water, it evaporates 
practically as if it were a single liquid and not 
a mixture. In France, it is denatured for mo¬ 
tor purposes by the addition of 10 liters of 90° 
wood alcohol, and 500 grams of heavy benzine, 
to 100 liters of 90° ethyl alcohol. In Germany, 
benzol is added to the extent of 15 per cent, for 
denaturing, no wood alcohol being used. In 
the United States the so-called “denatured’* 
alcohol, which is that used in the arts and in¬ 
dustries, is composed of ethyl or grain alcohol, 
to which have been added certain diluents cal¬ 
culated to make it unfit for drinking. The In¬ 
ternal Revenue regulations specify that to 100 
volumes of ethyl alcohol there must be added 
10 volumes of methyl (wood) alcohol and one- 
half of one volume of benzine, or to the same 
quantity of ethyl alcohol must be added 2 vol¬ 
umes of wood alcohol and one-half of one vol¬ 
ume of pyridine bases. 

As compared with gasoline as a fuel for in- 


12 


The Automobile Handbook 


ternal-combustion motors, alcohol exhibits sev¬ 
eral striking peculiarities. 

First, the combustion is much more likely to 
be complete. A mixture of 90° alcohol vapor 
and air will burn completely when the propor¬ 
tion varies from 1 of the vapor with 10 of air 
to 1 of the vapor with 25 of air, thus exhibiting 
a much wider range of proportions for combusti¬ 
bility than is the case with gasoline. As the 
combustion is complete, the exhaust is practi¬ 
cally odorless, consisting only of water vapor 
and carbon dioxide. 

Second, the inflammability of an alcohol mix¬ 
ture is much lower. This is due partly, no doubt, 
to the presence of water in the alcohol, which 
is vaporized with the alcohol in the engine and 
must be converted into steam at the expense of 
the combustion. 

For these reasons, the compression of an al¬ 
cohol mixture is carried far above that permis¬ 
sible with a gasoline mixture, without danger 
of spontaneous ignition. The rapidity of com¬ 
bustion of alcohol in an engine is considerably 
less than that of a gasoline mixture, and for this 
reason the speed of alcohol engines must be 
somewhat slow. 

The facts that alcohol of sufficient purity for 
use in engines can be produced from the waste 
products of many of the country’s industries, 
and at a nominal cost, and that many thousands 
of acres of land, unfit for the cultivation of 
first-class grain, etc., may be utilized for the 


The Automobile Handbook 


13 


production of vegetable matter rich in the ele¬ 
ments which form alcohol upon fermentation, 
lead to the supposition that within a few years, 
or as soon as there is a sufficient demand for 
alcohol to warrant the erection of special dis¬ 
tilleries, it may be purchased at such a low price 
that it will not only be commercially possible, 
but will in a measure force gasoline and other 
petroleum distillates from the field. 

A carbureter designed to operate with alcohol 
can always be used with gasoline, but the re¬ 
verse conditions are not true, that is, a gasoline 
carbureter will not operate successfully with 
alcohol, except in some rare instances. Alcohol 
evaporates slower than gasoline and its time of 
combustion is much slower, but it maintains its 
mean effective explosion pressure far better 
than gasoline. 

Explosive motors fitted with alcohol carbu¬ 
reters make far less noise than when using gaso¬ 
line as a fuel, due to the slower burning of the 
explosive charge, they also make less smoke 
and smell. 

The jet or spray of a float-feed carbureter will 
have to pass nearly 40 per cent, more liquid 
fuel than when using gasoline, consequently the 
opening in the nozzle must be proportionally 
larger. 

A carbureter using alcohol must be fitted with 
some form of device to heat the alcohol to en¬ 
sure rapid evaporation—this is usually done by 


14 


The Automobile Handbook 


surrounding the mixing-chamber with an ex 
haust-heated jacket. 

The same quantity of alcohol will only take 
a car two-thirds of the distance that gasoline 
will, hence greater storage capacity would be 
needed on a car using alcohol as a fuel. 

An explosive motor designed to use alcohol 
requires a greater degree of compression than a 
motor of the same bore and stroke designed to 
use gasoline, in order to develop the same 
power. 

Alloys. In the following pages are given the 
compositions of the principal alloys (except 
Steel, which see) as recommended by the Society 
of Automotive Engineers. 

Aluminum .—Where a tough, light alloy, pos¬ 
sessing a high degree of strength combined with 
great lightness is desired the composition can 
be 90.0% aluminum and 7.0 to 8.5% copper. 

An alloy possessing strength, closeness of 
grain and freedom from blowholes in casting 
is composed of 84% tin, 9% antimony and 
zinc, 2.0 to 3.0% copper and not to exceed 0.4% 
of manganese. 

Bearing Metals .—A babbit metal suitable for 
the connecting rod linings of motor bearings or 
for any service of severe operating conditions 
is composed of 84% tin, 9% antimony and 
7% copper. 

A white brass for use in engines is made 
from 65% tin, 28 to 30% zinc and 3 to 
6% copper. 


The Automobile Handbook 


15 


Phosphor bronze is a composition having good 
anti-friction qualities combined with the ability 
to stand up under heavy loads and hard usage. 
It is used against hardened steel. The com¬ 
position consists of 80% copper, 10% tin and 
10% lead. 

Brass and Bronze .—Red brass, suitable for 
light bearings and castings and having good 
machining qualities is composed of 85% copper, 
5% tin, 5% lead and 5% zinc. 

Yellow brass for general brass casting work 
consists of 62 to 65% copper, 36 to 31% zinc and 
2% to 4% lead. 

A hard cast bronze suitable for severe work¬ 
ing conditions under heavy pressures and high 
speeds, also for light gears, valves, etc., is com¬ 
posed of 87 to 88% copper, 9.5 to 10.5% tin 
and 1.5 to 2.5% zinc. 

Gear bronze, for use in severe service and 
where quiet running is required, consists of 88 
to 89% copper, 11 to 12% tin and 0.15 to 0.30% 
phosphorous. This bronze is generally used in 
gears and worms. 

Manganese bronze is understood to mean a 
metal constituted principally of copper and zinc 
in the approximate proportion of 60 and 40, 
small quantities of iron and variable quantities 
of manganese being present. This metal jis 
used in castings where strength and toughness 
are required. It has a tensile strength of 
60,000 pounds per square inch. 


16 


The Automobile Handbook 


Aluminum alloys are commonly used in auto¬ 
mobile construction, these including the various 
grades known by the name aluminum, also 
aluminum bronze which contains a considerable 
percentage of copper and has been used simi¬ 
larly to manganese bronze. Magnalium is an 
aluminum alloy containing magnesium. It is 
lighter than aluminum and has greater strength. 
It is used for pistons. 

Brass of all kinds has copper for its base and 
zinc as its principal alloy. All bronzes have 
copper as the base and tin as the principal alloy. 
Gun metal is a bronze. Manganese bronze is 
in reality a form of brass. Tobin bronze, Delta 
metal, Tensilite, etc., are special alloys manu¬ 
factured under these trade names by certain 
makers. Monel metal is a natural alloy of cop¬ 
per and nickel which is mined and refined with¬ 
out changing the proportions. 

Alternating Current, Use of. It is not only 
useless but absolutely injurious to attempt to 
charge a storage battery directly from an alter¬ 
nating current circuit. This can only be done 
by means of a rotary converter, which is in 
reality a motor-generator, receiving its power 
from the alternating current and transforming 
it into a direct current which can be used to 
charge the batteries. 

Aluminum. A soft ductile malleable metal, 
of a white color, approaching silver, but with a 
bluish cast. Very non-corrosive. Tenacity 
about one-third that of wrought iron. Specific 


The Automobile Handbook 


17 


gravity 2.6. Atomic weight 27,1. It is the 
lightest of all the useful metals, with the excep¬ 
tion of magnesium. 



Fig. 2 

Direct Current Impulses 


Aluminum Solder. The following forjnula is 
for a solder which will work equally well with 
aluminum or aluminoid: Tin, 1.0 parts—cad¬ 
mium, 10 parts—zinc, 10 parts—lead, 1 part. 
The pieces to be soldered must be thoroughly 












18 


The Automobile Handbook 


cleansed and then put in a bath of a strong 
solution of hyposulphate of soda for about two 
hours before soldering. 

Ammeter, Use of. Ammeters are quite gen¬ 
erally used in connection with electric starting 
and lighting systems, either as a permanent part 
of the equipment, or as an attachment used dur¬ 
ing the process of trouble location. 

When possible the ammeter should be so con¬ 
nected that it will measure all of the current 
flowing into the battery from the generator and 
so that it will measure all current leaving the 
battery except that used for starting the engine. 
An ammeter sufficiently great in capacity to 
measure the heavy flow during the cranking 
operation would not accurately measure the com¬ 
paratively small currents used for charging and 
lighting. It is therefore necessary to find a wire 
on the equipment that carries all of the charging 
current and all of the current for lighting and 
accessories, but which does not carry starting 
current. This attachment may usually be made 
by following one of the large cables from the 
battery until a smaller line branches from this 
cable at some terminal or junction. The am¬ 
meter should then be attached in this smaller 
line and as close to the large battery cable as 
is possible. 

Should the charging wires and the lighting 
wires be connected at different points, it will 
not be possible to make a single connection of 
the ammeter without changing the wiring. This 


The Automobile Handbook 


19 


is also the case with many motor-dynamo systems 
in which no exposed line can be selected which 
carries only charging and lighting current. 

Ammeter, Construction of. Ammeters for 
automobile use are constructed on the principle 



AMMETER 


Fig. 3 

of the D’Arsonval galvanometer with a perma¬ 
nent magnetic field. The special feature is a 
small oscillating coil mounted on cone-point 
bearings surrounding a stationary armature 
which is centrally located between the pole- 
pieces of a permanent magnet, with a' pointer 
or index-finger which indicates the electrical 
variations on a graduated scale. 
































20 


The Automobile Handbook 


The construction of an ammeter is fuliy 
show in the two views in Figure 3. The per¬ 
manent magnets used in its construction are of 
a special quality of hardened steel, made only 
for this purpose and possessed of great mag¬ 
netic permeability. The pole-pieces, which are 
of soft steel and well annealed, are attached to 
the inside of the lower part of the magnet legs, 
the joints between the pole pieces and the mag¬ 



net legs are usually ground to insure the full 
efficiency of the magnetic circuit. The soft iron 
core of the coil is for the purpose of rendering 
uniform the magnetic field in which the coil 
must oscillate. A coil of insulated wire is 
wound upon the stationary armature at right 
angles to its axis, in the same manner that 
thread is wound upon a spool, and is short-cir¬ 
cuited on itself, that is to s#y, the ends of the 
wire forming the coil are connected together. 
This coil of wire is for the purpose of choking 

















The Automobile Handbook 


21 


the magnetism induced'in the stationary arma¬ 
ture by the oscillating coil, as it generates what 
are known as eddy currents within itself, thus 
making the instrument periodic, or dead-beat, 
in its indications. Around the armature core 
and outside the short-circuited coil of wire is 
wound the active or oscillating coil and at right 
angles to the direction of the winding of the 
first coil. The oscillating coil consists of a num¬ 
ber of turns of fine insulated copper wire, to 
which the current is conveyed through the me¬ 
dium of the controlling springs at each end of 
the spindle, which is in two parts and con¬ 
nected together by a suitable sleeve of insulat¬ 
ing material, as shown. 

The pointer or index-finger is made with a 
boss or hub to go over the end of the spindle of 
the active coil and also has an extension with a 
small counterweight or balance, so that the 
pointer may be accurately adjusted. 

The only difference in the construction of a 
voltmeter and an ammeter is that in the former 
the active or oscillating coil is in series with a 
high resistance, while in the latter it is con¬ 
nected across the terminals of a shunt-block. 
The voltmeter is in reality an ammeter, the re¬ 
sistance serving to keep the amperage in step 
with the voltage. 

Reference to the three views, marked re* 
spectively A, B and C in Figure 4, will show 
clearly the principle of the operation of an 
ammetev or voltmeter, and the reason thatAhey 


22 


The Automobile Handbook 


record the current strength or pressure of an 
electric current accurately. 

Ammeters are of two kinds, the double-beat 
type, as shown in Figure 3, which indicates the 
current strength or number of amperes flowing 
in the electric circuit, without any regard to 
the polarity of the terminals of the circuit, by 
the pointer or index-finger moving either to the 
right or to the left of the zero position. The 



single-beat type of ammeter only ^records in 
one direction, by the pointer moving from the 
left to the right of the graduated scale of the 
instrument, consequently the polarity of the 
terminals of this type of ammeter are marked 
on its outer casing and the polarity of the ter¬ 
minals of the electric circuit must consequently 
be determined before connecting them with the 
ammeter. 


















The Automobile Handbook 


23 


Ampere. The unit of electric current flow. 
An ampere is that volume of current which 
would pass through a circuit that offered a re¬ 
sistance of one ohm, under an electromotive 
force of one volt. 

Ampere-hour, Definition of. The term am¬ 
pere-hour is used to denote the capacity of a 
storage or a closed-circuit primary battery for 
current. A storage battery that will keep a 2 
ampere lamp burning for 8 hours is said to 
have a 16 ampere-hour capacity. In a similar 
manner an 80 ampere-hour battery would ope¬ 
rate the same lamp 40 hours. The voltage of a 
battery does not enter into the calculation of 
its ampei*e-hour capacity. 

Annealing. A process of heating by means 
of which metals are relieved of internal strains 
and distortions. In some cases annealing is 
employed only to relieve strains, while in other 
cases it is desired to soften the metal sufficiently 
to allow its working. 

Steel to be annealed is first heated to a dull 
red, the temperature being increased slowly so 
that all parts of the piece will have time to 
reach the same temperature at very nearly the 
same time. This heating is usually done in 
some form of oven by which the work is pro¬ 
tected against air currents. 

The work may be withdrawn from the fire 
or oven after reaching the desired temperature 
and allowed to cool in the air until no red can 
be seen when held in a dark place. If, upon 


24 


The Automobile Handbook 


touching a pine stick to the steel, the wood does 
not smoke, the cooling may be completed in a 
water bath. 

Better results will be secured if the cooling 
time is extended by placing the work in a bed of 
ashes, charred bone, asbestos fibre, lime, sand 
or fire clay. The steel should be well covered 
with the heat retaining material and allowed to 
remain until cool. The greater the length of 
time between red heat and final coolness, the 
better will be the results of the annealing. 

While steel is annealed by heating and cool¬ 
ing slowly; copper or brass is annealed by 
bringing to a very low red heat and then cooling 
quickly by plunging into cold water. 

Armatures, Dynamo. The armature, or re¬ 
volving member of lighting dynamos, is com¬ 
posed of a core made from wrought iron or mild 
steel. It is customary to make this core by as¬ 
sembling a sufficient number of thin plates 
made in the form of the cross section of the 
core, these plates being covered with an insulat¬ 
ing composition and then fastened together on 
the shaft. This construction prevents the for¬ 
mation of harmful “eddy currents” within the 
metal. 

The assembled core has a number of slots run¬ 
ning lengthwise of its body and in these slots 
are placed the armature coils or winding of in¬ 
sulated wire. The coils are then connected to 
a commutator mounted on one end of the shaft 
in such a way that the current generated may 
be collected by the brushes. 


The Automobile Handbook 


25 


Armatures, Slotted and Shuttle Types of. 

An armature is the rotating part of a dynamo 
or electric motor which generates electricity or 
develops power. 



The armature shown at right of Fig. 6 is 
known as the Siemen’s H or shuttle type and is 
the simplest form of wire-wound armature 
known. The current given by this form of 
armature is of the alternating type and is con¬ 
verted into a direct-current, when desired, by 
means of a two-part commutator on the arma¬ 
ture shaft. 

The slotted type of armature shown at the 
left of Fig. 6 has a more intricate sys¬ 
tem of winding than the shuttle type just de¬ 
scribed. It has, however, a far greater elec¬ 
trical efficiency and gives off a steadier current 
than the shuttle type. It is the form most gen¬ 
erally used for automobile and street railway 
motors. Like the shuttle type of armature, the 
current generated by the slotted type of arma¬ 
ture is alternating, and is converted into a di¬ 
rect current by means of a commutator of very 
implicated form. 




26 


The Automobile Handbook 


Automobile. An automobile is composed of 
five parts, these including; first the power plant, 
second the transmission system, third the run¬ 
ning gear, fourth the control parts and fifth 
the body. 

The power plant comprises the engine 
together with the parts required in order that 
the engine may generate power. The engine 
auxiliaries are: an oiling system for lubricating 
the moving parts, a cooling system for maintain¬ 
ing a temperature of the engine cylinders at 
which lubrication may be secured, a fuel sys¬ 
tem by means of which the engine is furnished 
with a combustible gas, and an ignition system 
which causes an electric spark and ignites the 
fuel. 

The transmission system includes all of the 
parts which carry power from the engine to the 
driving wheels. These parts include the clutch 
by means of which the engine may be allowed 
to run with the car idle, a change speed gear 
which provides different ratios of relative speed 
between engine and driving wheels and also a 
reverse motion of the car, a differential for 
allowing one rear wheel to turn faster than the 
other, and a driving axle. 

The running gear includes all of the parts 
which support the power plant, transmission 
system control parts and body. It consists of 
the axles, wheels, tires, springs and the frame 
with its brackets. 


The Automobile Handbook 


Axle, Front. So far it has not been found 
practical to combine the tractive and steering 
functions of an Automobile in one set of wheels 
and axle. Therefore it is necessary to use a 
rigid front axle with knuckle jointed spindles, 
for steering purposes, and utilize the tractive 
power of the rear wheels only to propel the 
ear. Some of the earlier forms of steering 
axles had the wheel pivots inclined so as to 
bring the projection of the pivot axis in line 
with the point of contact of the wheel with the 
ground, but as such constructions have not 
proved satisfactory they have in most cases 
been abandoned. 

























28 


The Automobile Handbook 


In Figures 7 and 8 are illustrated four 
styles of front axles with steering-pivot ends: 
A shows a solid axle of square section, with 
the steering-pivot jaws and axle proper, of a 
single forging—B represents an axle of tubular 
cross-section with the steering-pivot jaws bored 



Fig. 8 


out to receive the tubular axle which is firmly 
brazed therein—C shows another style of tubu¬ 
lar axle, in which the steering-pivot jaw ends 
are turned down to fit the inside diameter of 
the tube and are also brazed in position, while 
D illustrates a one-piece axle with vertical hubs 


























The Automobile Handbook 


29 





STEERING KNUCKLE 


Fig. U 














































30 


The Automobile Handbook 



Fig. io 







































The Automobile hu/nauooh 


31 


instead of jaws, which carry L-shaped steering- 
pivots, instead of the usual form of knuckles. 

Steering Knuckles. In order to obtain ease 
of operation and secure the shortest turning 
radius with the least movement of‘the steering 
wheel or lever, the knuckle of the steering pivot 
should be as close to the center of the wheel 
as is possible. It is also cf great importance 
that the steering knuckles should be as heavy 
as is practically consistent with the size and 
weight of the car for .which they are intended. 
If this imporant point be neglected, rapid wear 
and probable fracture of the knuckles may be 
looked for. 

A steering knuckle with a spindle and pivot 
of T shape is shown in Figure 9. The spindle 
and pivot N and the steering arms 0 are usually 
a one-piece forging. The steering arms 0 are 
connected by means of a suitable distance rod 
and the steering lever P. is attached to one of 
the pivots N by turning a shoulder upon it and 
pinning and brazing the steering lever and pivot 
hub together. 

Figure 10 shows a steering knuckle with 
spindle and pivot of L shape. The steering arm 
R goes on the lower end of one pivot Q only, 
the other pivot having the combined steering 
arm and ever S on its lower end. The steering 
arms being detachable, the device may be oper¬ 
ated from the right or left hand side by simply 
exchanging the levers R and S. The steering 
lever S has a ball upon its outer end to fit in the 


The Automobile Handbook 







































The Automobile Handbook 


33 


socket on the connecting rod of the steering 
mechanism. 

Axles, Rear. The following definitions apply 
to the forms of rear axles that are now and 
have been in use on shaft-drive cars. 

A “live axle” (no longer used) is one in 
which the driving member is carried by a bear¬ 
ing at each end, the outer end carries the wheel 
and the inner end the differential. 



Fig. 12 


Semi-Floating Rear Axle 
A “semi-floating axle,” Fig. 12, is one in 
which the driving member is carried on one 
bearing at its outer end and with the inner end 
supported by the differential. The outer end 
carries the wheel. 

A “three-quarter floating axle,” Fig. 13, is 
one in which the driving member is carried by 
the differential at its inner end and at the outer 






























34 


The Automobile Handbook 


end is carried by the hub flange, the flange itself 
being bolted to the wheel. The wheel is then 
carried by a bearing that runs on the outside of 
the end of the axle housing tube. 



A “full floating axle,” Fig. 14, is one in which 
the driving member is carried by the differential 
at its inner end and at the outer end is carried 
by a jaw clutch, the clutch itself being engaged 









































The Automobile Handbook 


35 


with and meshing with the wheel hub. The 
wheel is then carried on two bearings that run 
on the outside of the axle housing tube. With 



Bearings 

this construction, the drive shaft may be entirely 
withdrawn from the car without disturbing the 
wheel or other axle parts. 

































36 


The Automobile Handbook 


In this case the tube is reduced in diameter 
to take the bearings, and the shoulder so 
formed is taken advantage of in the process of 
providing for thrust. The shaft has no work to 
do excepting to take torsional moments, and 



the design throughout includes drop forgings 
of steel and drawn-steel parts. The inner race 
of the ball bearings is a sufficiently heavy tube, 
but it is not shaped in such a way as to act as a 
“preventer bearing,” hence complete depend¬ 
ence is placed on the ball bearings and they arc 









































The Automobile Handbook 37 

made large enough to take the responsibility. 

Axle, Rear, Three-Quarters Floating. In 
this design, Fig. 13, the axle housing is ex¬ 
tended outward to a point in line with the out¬ 
side surface of the wheel, and the outer end is 
made of a diameter just large enough to allow 
the axle shaft to pass through it. Mounted on 
the outer end of the axle and directly in the 
center of the wheel is a single hearing, usually 
of the annular ball type. The wheel spokes are 
mounted in the hub flange in the usual manner 
and the flange is carried upon the outer surface 
of the bearing mentioned above. A large hub 
forging is bolted to the wheel flange and the 
bolts pass through the spokes which hold the 
brake drum on the inside. The outer end of 
the driving shaft is fastened into this hub forg¬ 
ing by a key way and taper; the inner end of 
the driving shaft is carried by the differential 
in the same manner as with a full floating type. 
It will therefore be seen that the radial load of 
the wheel is carried on the single bearing at 
the end of the housing, and this bearing is also 
required to carry the end thrust. The binding 
strains that are imposed upon the wheel when 
turning corners, for instance, are provided for 
through the rigidity of the driving shaft, which 
is fastened solidly into the wheel hub at its 
outer end and which is carried by the differen¬ 
tial at its inner end. This gives a leverage equal 
in length to the distance between the outer bear¬ 
ing and point of support in the differential. 


38 


The Automobile Handbook 


Axle, Rear, Internal Gear. The internal g^a> 
type of rear axle as used on commercial cars 




Fig. 17 

Internal Gear Drive 

consists of two principal parts, one being a load 
carrying member consisting either of an “I” 
beam or tubular member on which the springs 




The Automobile Handbook 


39 


and road wheels are mounted, and the other 
being a driving member which is much like the 
ordinary bevel gear type of rear axle with the 
exception that the outer ends of its shafts are 
fitted with spur gears which drive internally 
toothed ring gears, these ring gears being in 
turn fixed to the driving wheels of the car. The 



principle of such an axle is shown in Figure 16 
which illustrates the application of the gearing. 

The relation of the driving parts is shown in 
Figure 17, A being the small spur gear carried 
by the ends of the driving shafts, B the load 
carrying member and C the internal gear fixed 
to the wheel. Depending on the position of 







40 


The Automobile Handbook 



Fig. 19 

Internal Gear Rear Axle 


































































































































































































The Automobile Handbook 41 

the driving member, ahead of or behind the 
load carrier, the spur gear A will be ahead of 
or behind the load member. Details of the con¬ 
struction at the wheel are shown in Figure 18 
which illustrates a type of axle (Russell) hav¬ 
ing the driving member in front of the load 
carrying tubular axle. It will be noted from 
this illustration that a comparatively great gear 
reduction is secured between the spur gear and 
the internal gear, leaving a much smaller reduc¬ 
tion to be obtained between the bevel gears at 
the center of the driving member than would 
be the case with any form of single reduction 
employing spur or bevel gears. 

In Figure 19 is shown a plan view of the 
axle having the driving unit ahead of the load 
carrier. The comparative size of the bevel pin¬ 
ion and gear in the differential housing indi¬ 
cates the small reduction at this point. 

Figure 20 shows the construction of an 
internal gear axle having the live axle back of 
the “I” beam load carrying member (Torben- 
sen). In this case the small spur gear meshes 
with the internal gear at the rear side. 

Because of the greater part of the reduction 
being obtained at the wheel, the driving shafts 
in internal gear axles are lighter than the cor¬ 
responding parts in single reduction axles and 
in general, for a given load carrying capacity, 
these axles are found to be comparatively light 
in weight. This advantage is in part balanced 
by the increase in the number of gears, bearings 
and related parts. 


42 


The Automobile Handbook 


« 



Fig. 20 

Internal Gear Rear Axle 














































































































Fig. 21 

Truck With Internal Gear Axle 


The Automobile Handbook 


43 


















































44 


The Automobile Handbook 


Figure 21 shows the application of another 
form of internal gear axle having a front 
mounted drive member (Clark) on a motor truck 
chassis. 



Fig. 22 

Worm Drive for Rear Axle 


Axle, Rear, Worm Driven. The worm type 
of rear axle is one of the best known and most 
widely used for commercial cars and electric 
vehicles, while it also finds a limited applica¬ 
tion on gasoline cars. The worm driven axle 
is especially suited to heavy loads and low 
vehicle speeds because of its ability to provide 
a great reduction of speed between the driving 
and driven shafts together with mechanical 
simplicity. 



































The Automobile Handbook 


45 


The principle of the generally adopted con¬ 
struction is shown in Figure 22 which illustrates 
a worm mounted above the worm wheel. The 
differential and the remaining parts of the axle 
are similar to the corresponding parts as found 
in the ordinary form of bevel gear construc¬ 
tions. The mounting of the worm must provide 



Fig. 23 

Ball Bearing Mounting of Worm Gear 



Fig. 24 

Exterior of Worm Drive Axle 


for withstanding a heavy end thrust inasmuch 
as it is the push of the worm against the gear 
which must drive the car. In top-mounted 
worms, the type generally used, the thrust of 
driving the car forward is taken at the rear of 
the worm, while in a bottom-mounted worm it 



















46 


The Automobile Handbook 


is taken at the front. With ball bearing mounted 
worms, the thrust from either direction, travel¬ 
ing forward or backward, is taken principally 
by the rear bearing by fixing the worm shaft so 
that it is held against lengthwise movement by 
this bearing only, the front bearing being left 
free to float and carry only the radial load. 

Figure 23 shows both a side and rear end 
view of the application of worm drive in a 



Fig. 25 

Removal of Worm and Worm Carrier 


truck axle. It will be seen that thrust bearings 
of ample size are placed at each side of the dif¬ 
ferential and worm gear in spite of the fact that 
the side thrust is less than with bevel gear axles. 

Figure 24 shows the external appearance of 
a complete worm drive axle (Sheldon) while 
Figure 25 shows the worm, worm wheel, dif¬ 
ferential and their carrier lifted part way out 
of the top opening irr the main axle housing. 





Roller Bearing Worm Drive 


































































































































































48 


The Automobile Handbook 


The type of worm commonly employed 
■requires practically no adjustment for meshing 
because the wear is distributed over such large 
surfaces that the initial setting is maintained. 
The large contact area and low unit pressure 
allow the use of dissimilar metals against each 



Fig. 27 

Roller Bearing Mounting of Worm 


other, steel being used for the worm and bronze 
for the worm gear in almost all cases. 

The worm gear is quiet in service and per¬ 
mits of complete enclosure against dirt and 
dust. These features, together with fewness of 
parts due to the single reduction are among its 












































The Automobile Handbook 


49 


advantages. The greatest fault with the worm 
gear axle is its weight in proportion to the load 
carried, this weight being required because of 
the loads imposed on the slowly moving parts. 
Great power can be exerted through a worm, a 
fact that is familiar to most people because of 
the use of various forms of screw and worm 
gearing to handle heavy loads. 



Fig. 28 

Worm Drive Axle With Spur Gear Differential 


Figure 26 shows a rear end section of a worm 
driven rear axle whose parts are carried by 
roller bearings of the tapered type. Figure 27 
shows a side elevation of the same axle (Tim¬ 
ken) and illustrates the method of taking the 
forward driving thrust on the rear bearing of 
the worm shaft and the reverse thrust on the 
forward bearing, this method being necessary 
because of the fact that taper roller bearings 





















50 


The Automobile Handbook 


take thrust in but one direction. In the axle 
shown the comparatively light thrust from the 
sides of the worm gear is taken by opposed 
roller bearings. 

All of the axles shown and most of those in 
use employ what is called a straight worm, that 
is, a worm having a straight face and a thread 
parallel on its outside edges to the worm axis. 


Fig. 29 

Bottom Mounted Worm 

This type avoids the necessity for great ac¬ 
curacy in end adjustment. 

In Figure 28 is shown a rear elevation of a 
worm drive axle (Pierce) using ball bearings 
and spur gear differential. 

Figure 29 illustrates the method of carrying 
the worm below the worm wheel, a practice 
which is not commonly found except in a few 
electric cars. Here it will be seen that the large 
thrust bearing is placed ahead of the worm itself. 
It is claimed for the underneath worm that it 
is better lubricated because the bath of oil 
always surrounds the surface in contact. 
















The Automobile Handbook 


51 


Batteries—Dry. A dry battery of the usual 
type consists of a zinc cell, which forms the 
negative element of the battery. 


+ 



Fig. 31 

Section Through 
Dry Cell 

Dry Batteries are very generally used on 
moderate speed and low-priced cars. They are 
simple in construction, comparatively simple in 
operation, and their action is easy to under¬ 
stand. Each cell is composed of three elements: 
The carbon, the zinc, and the electrolyte. The 
carbon usually takes the form of a round stick 
placed in the center of a cylindrical vessel made 
of zinc in sheet form. The space between the 
carbon and the zinc is filled with the electrolyte, 






















52 


The Automobile Handbook 


generally a solution of sal-ammoniac, which is 
poured in on crushed coke. The top is clos'ed, 
or rather sealed, with pitch to prevent the loss 
or evaporation of the liquid. Through this, 
project the ends of the carbon and the zinc, these 
being formed into binding posts for holding the 
wires. As this holding of the wires must be an 
intimate relation, the usual form is a threaded 
shank upon which a pair of nuts are mounted. 
Between these the wire to be connected is 
crushed or compressed bj^ the moving together 
of the nuts. 

The two poles or binding posts are called the 
positive and the negative, and are indicated by 
the + sign for the former and the — sign for 
the latter. Carbon being the positive element, 
the + sign attaches to it. Now, the act of con¬ 
necting these terminals together so as to allow 
a flow of current allows of two different meth¬ 
ods of procedure, a right and a wrong way, it 
is true, but that was not what was meant. 

In one respect dry batteries have a decided 
advantage over storage batteries for ignition 
purposes, from the fact that on account of their 
high internal resistance they cannot be so 
quickly deteriorated by short circuiting. 

On account of this high internal resistance, 
dry batteries will not give so large a volume of 
current as storage batteries, but a set of dry 
batteries may be short circuited for five min¬ 
utes without apparent injury and will recuper¬ 
ate in from twentv to thirty minutes, while a 


The Automobile Handbook 


53 


storage battery would in all probability be 
ruined under the same conditions. 

It is often desired to secure a greater voltage 
than one cell will give, or else to secure a source 
of current that will give a greater time of ser¬ 
vice than can be secured from the single cell. In 
either case, it is customary to combine two or 
more cells in certain definite combinations and 
connect them with each other in such a way 
that the desired voltage or length of life is 
realized. It is possible to make such combina¬ 
tions by using either dry or storage cells, 
although storage cells are usually boxed after 
forming. 



Fig. 32 

The Ordinary Battery Connection, in Series 
Two methods are usually employed, viz.: 
series, and multiple, or parallel. To connect 
dry batteries in series, the terminals are joined 
alternately, that is, the zinc of the first is con¬ 
nected to the carbon of the second, the zinc of 
the second to the carbon of the third, etc. 

When so joined, the positive element is left 
free at one end, and forms the positive terminal 









54 


The Automobile Handbook 


of the group, which is then considered as a unit. 
The other free end (the negative) forms the 
negative terminal of the unit, see Fig. 32, which 
shows four cells connected in series. 

Figure 33 shows four cells connected in paral¬ 
lel which means that all of the positive termi¬ 
nals are connected to one common wire, and all 
negatives are connected to another wire. 

This mode of wiring up the cells gives a 
smaller output for the group. Thus if the in¬ 
dividual batteries have an internal resistance 



Fig. 33 

Parallel Connections are Not as Frequently Used 


which is low in comparison with the external 
resistance, the total output will be but slightly 
more than that of a single cell. If, on the other 
hand, the internal resistance is high relative ta 
the external, the current will be roughly pro¬ 
portional to the number of cells. 

Where the cells are divided into sets or groups 
of a small number (four is usual), and more than 
one of these sets are used at a time, there are 
again two methods of joining them. These two 
are the same as before, viz., series and multiple. 









The Automobile Handbook 


55 


The former is very seldom used, if ever, but the 
other is rather common. When two or more 
sets of batteries, themselves connected in series 
are, as sets, joined in multiple the whole is 
spoken of as connected in series-multiple. 



Fig. 34 


Batteries—Storage. A storage battery as 
used in ignition service, is usually of the lead- 
acid type, in which the electrolyte is sulphuric 
acid and water of a density about 1.2— specific 
gravity. The plates are of: two classes—posi¬ 
tives and negatives—there being one more nega¬ 
tive than positive in each nesting in a ceil. 
The elements of a cell of storage battery are 




































56 


The Automobile Handbook 



given in Fig. 35, and consist of the following: 
Positive plates A, of which there is one fewer 
than of negatives; negative plates B, of which 
there is always one more than positives; sepa- 


Fig. 35 

Elements of Assembled Battery 

rators C, which may be of wood, rubber, oi 
other suitable material, and if of wood must be 
treated; positive strap D, the function of which 
is to connect all the positive plates, across the 







The Automobile Handbook 


57 


top, into electrical relation; negative strap E, 
the function of which is to connect all the nega¬ 
tive plates, at the top, in electrical relation; bat¬ 
tery jar P, made of rubber composition, light, 
strong and acid proof; cover for the jar G, with 
holes for the terminals of the elements, and a 
vent; assembled cell of battery II, showing the 
elements in place, separated, with cover on; 
ready for connections; and a battery box I, of 
oak, usually contrived to hold three cells of 
battery, sometimes two. 

The positive and negative plates, called ele¬ 
ments, consist essentially of a grid in each case, 
made of lead-alloy, in which antimony is used 
to engender stiffness. The grids are in divers 
forms, depending upon the views of several 
makers, the idea being to afford space for the 
active material, and to lock the same in, so that 
it will not drift out, as it is prone to do, under 
the action of the charging, and discharging cur¬ 
rent. Surface is the great requisite, and it is 
the aim to afford the maximum area of the fin¬ 
ished plates, per pound of active material used; 
limiting the weight of the supporting grid, in 
so far as it is possible to do so. 

The voltage of a battery of this type is usu¬ 
ally 2.2 volts when the circuit is closed, but it 
drops to 2 volts within the first hour of using, 
which pressure it usually maintains during the 
next 5 hours, after which the voltage declines 
at a rapid rate. 

Adding Water to Cells. In service water 


58 


The Automobile Handbook 


will have to be added to the cells to compensate 
for evaporation, and for the loss that takes place 
during charge, brought about by the entraining 
of water with the bubbles of gas that shoot off 
and out of the jars, if they are open, that is to 
say, if the covers are removed before and left 
off during charging, which is not usually the 
case. The result in any event is in favor of in¬ 
creasing strength of the electrolyte, and water 
will have to be added from time to time in order 
that the plates may not be exposed to the atmos¬ 
phere above the line of active material; which 
is a point that must be cared for if the battery 
is to last for a long time. The water so added 
should be pure—distilled—and the right quan¬ 
tity to add, will be determined by means of a 
hydrometer placed in each cell between the sepa¬ 
rators if there is sufficient room, or the electro¬ 
lyte may be withdrawn through the utility of a 
gun made of hard rubber with a long slender 
neck. The test should be made when the bat¬ 
tery is charged and every cell should be exam¬ 
ined rather than to test one cell and conclude 
that all are in an average condition. 

Storage Batteries—Care of. Among the 
troubles that ultimately attend batteries in serv¬ 
ice the following are the most conspicuous: 

Hardening of negative elements; local action; 
buckling of plates; shedding of active material; 
sulphation; rewrsal of negative elements; dis¬ 
integration of grids; protruding active mate¬ 
rial; deformation of separators; broken jars: in* 


The Automobile Handbook 


59 


cipient short circuits; defective electrical con¬ 
tact : loss of capacity; loss of voltage; corrosion 
of plates, and needle formations. 

Hardening of the negative elements will fol¬ 
low if they are exposed to air, as when the elec¬ 
trolyte is allowed to fall below the level of the 
plates, from any process that will produce over¬ 
oxidization if the temperature is allowed to in¬ 
crease much above 90 degrees Fahrenheit. 
When the negative elements are hard, to reduce 
them back to the normal condition, assuming 
the process is not too far gone: Remove the 
elements from the jar, place the negatives in a 
cell, with dummy positives, and charge until 
the negatives are corrected, taking care not to- 
charge at a too high rate. High temperature 
and excess boiling should be avoided. If the 
negatives are charged in their own cell with 
the regular positives the positives will be dam¬ 
aged by the excess charging that will be neces¬ 
sary to reduce the negatives. When the nega¬ 
tives are sufficiently charged to correct the evil 
they may be returned to their own cell, and 
when connected up with the positives the cell 
will be ready to go into service again, if in the 
meantime the positives are given such attention 
as their condition would seem to indicate. Local 
action, following impurities in the electrolyte, 
will only be prevented as much as it is possible 
to do so when the electrolyte is removed and 
pure electrolyte substituted in its stead. This 
should be done when the cells are fully charged 


60 


The Automobile Handbook 


The electrolyte will hold most of the impurities 
when the battery is in the fully charged state. 

Buckling of plates, when batteries are defec¬ 
tive in design, rather than in cells of normal 
characteristics, is a trouble that will follow in 
any cell if the discharge is allowed to extend 
below 1.8 volt as indicated by the cadmium test, 
rather than by the usual potential difference 
reading across the two sets of elements in the 
cell. If the rate of discharge is excessive, a 
condition that is not likely in ignition work, 
buckling will follow also. Short-circuiting the 
elements to see if the battery is alive will tend 
to buckle the plates, due to the heavy discharge, 
and the uneven rate of discharge over the sur¬ 
faces of the elements. In defective construction, 
if the active material is not of the same porosity, 
thickness, and in the same condition all over the 
surfaces of the plates, buckling will follow. 

Shedding of the active material, to a slight 
extent, is a normal condition of batteries; and 
to prevent trouble due to incipient short cir¬ 
cuits, such shedding is cared for by having a 
space in the bottom' of cells to hold such 
shedded material. When elements are of in¬ 
ferior design and improperly constructed the 
active material will shed at a rapid rate, and 
the user of the battery can do nothing more than 
demand a new battery to replace the defective 
one. If charging is done at a too rapid rate 
the active material will be loosened by the rap¬ 
idly escaping gas, and even on discharge, if the 


The Automobile Handbook 


61 


rate is high, the shedding of active material is 
likely to follow. 

Sulphation, which is a normal expectation 
during discharge of a battery, introduces serious 
complications under certain conditions as when 
the active material is not in intimate contact 
with the grids thus allowing the electrolyte to 
get between the grids and the active material, 
with the result that sulphate, which is a high 
resistance material, isolates the grids and re¬ 
duces the efficiency of the cell in two ways; 
first, by increasing the ohmic losses, and, second, 
by lowering the chemical activity. Excess sul¬ 
phate is prone to form when the electrolyte is 
out of balance, and one of the best ways to 
abort this action is to keep the electrolyte with¬ 
in the prescribed limits of strength. If sulphate 
is allowed to form until white crystals show over 
the surfaces- of the plates, it is highly improb¬ 
able that the cells will ever be of sufficient serv¬ 
ice to warrant continuing them in service. The 
only way to afford relief lies in reducing the 
growth of sulphate by continuous charging the 
sick elements in a cell with dummies until the 
sulphate is reduced. A slow rate for a long 
time may bring about a reform. 

Negative elements to be reversed must be 
below capacity, or the cells must be discharged 
to' zero and then reversed. In charging it is 
always necessary to make sure that the connec¬ 
tions are made in such a way that current will 
flow into the battery, rather than out of it. Volt- 


62 


The Automobile Handbook 


meters in which permanent magnets are used 
will serve as polarity indicators, and with them 
it is possible to proceed with safety. If a bat¬ 
tery is connected up in reverse when it is put on 
charge, instead of being charged it will be dis¬ 
charged, and then charge in reverse. While it 
is discharging it will deliver current to the line. 

Disintegration of grids will follow if the im¬ 
purities are allowed to enter the electrolyte, as 
iron, etc. Continued charging will also have 
the effect of reducing the grids to form salts 
of lead. 

Protruding active material indicates a lack 
of binding relation between the girds and the 
active materials. It may often be replaced by 
compressing the plates in a plate press. Defor¬ 
mation of separators, when they are made of 
rubber compound, follows when, the cells are 
allowed to heat beyond a certain point. This 
trouble will be aborted if the cells are charged 
at a normal rate, and if the temperature is not 
allowed to increase beyond about 90 degrees 
Fahrenheit. When wood separators are used 
they will slowly rot and in time it will be neces¬ 
sary to replace them. 

Broken jars will allow the electrolyte to leak 
out, and frequently the fracture is but a minute 
crack, so that it is well to be on the lookout 
for just this kind of trouble. If the jars are 
properly nested and motion between them is 
prevented they will as a rule serve without 
breaking. 


The Automobile Handbook 


63 


Incipient short circuits are likely to go un¬ 
noticed. They are generally due to detached 
particles of active material that lodge between 
the plates/ especially in vehicle and ignition 
types, owing to the short distance separating 
the plates, and the use of separators, such as 
perforated rubber in the absence of wood, which 
have the virtue of being porous but too close to 
allow the active material to bridge across the 
space between the plates. 

Defective electrical contact is due to corrod¬ 
ing of joints that are not made by burning. 

Loss of capacity may be traced to such causes 
as: If the electrolyte is out of balance or below 
the level of the top of the plate; loss of active 
material from the grids; sulphate formed on 
the surfaces of the grids, isolating the active 
material; lack of porosity of the active material; 
impurities and sulphate clogging up the pores 
of the active material; low temperature; high 
temperature; persistent sulphation, and inter¬ 
cell leakage due to electrolyte spilled over the 
surfaces, especially if jars are in actual contact 
with each other. 

Loss of voltage, as distinguished from loss of 
capacity, follows in a battery when one or more 
of the cells are dead or below voltage. If one 
or more of the cells are reversed they will set up 
a counter-electro-motive force, and the over-all 
reading of the battery will be reduced accord¬ 
ingly. The remedy is obvious. All the cells 


64 


The Automobile HandboK 


should read the same way, and all should have 
the same difference of potential, respectively. 

In view of the sulphated condition that at¬ 
tends all batteries that are discharged at a low 
rate for a long time, as is the case in ignition 
work, it is necessary to charge at a low rate for 
a long time in order to reduce the sulphate, 
which is in persistent form and very difficult 
to reduce. It will not be enough to correct the 
strength of the electrolyte once during the 
charging process for the reason that it will be 
difficult, if not impossible, io ascertain the con¬ 
dition of the same with any degree of accuracy, 
and the necessity for noting strength two or 
three tim.es in the act of charging is apparent. 
When the battery is fully charged, which may 
take even sixty hours of continuous charging 
at a low rate, the electrolyte in every cell should 
stand at full strength, considering a state of 
full charge, and the color as well as other indi¬ 
cations of a full charge should be fully noted. 
Boiling at a slow rate should be tolerated for 
several hours, but the temperature should be 
held at about 90 degrees Fahrenheit during the 
entire time. If a battery is charged at frequent 
intervals it will last longer in service, give less 
trouble in charging and will be more reliable in 
service. It is well to begin charging directly a 
battery is taken out of service as any delay 
after that time will result in a marked deteriora¬ 
tion of the cells. 

When a car is put out of commission, even 


The Automobile Handbook 


65 


for a few weeks, the battery should be given a 
light discharge, and a subsequent charge as 
often as once a week, until it is again brought 
back into use. 

Storage Batteries — Charging. Positive 
plates in the charged state are of a velvety 
brown or chocolate color; negative plates have 
the color of sponge lead, which is very nearly 
light gray. When a battery is approaching a 
condition of full charge the color tones up quite 
noticeably, and it is possible to mistake a con¬ 
dition of full charge, if color alone is taken as 
the evidence; the exterior will have the appear¬ 
ance of full charge, since the active material, 
on the exterior surface, will reach its charged 
form first; if the thickness of active material on 
the grids is very thick, as it is likely to be in 
low discharge rate work, charging by color, 
as evidence of a state of full charge, will be to 
limited advantage. Details regarding the 
proper care and upkeep of storage batteries are 
given in the following pages. 

Storage Batteries—Testing. Tests for im¬ 
purities in the electrolyte may be made as fol¬ 
lows. For iron; 

Neutralize a quantity of the electrolyte to be 
investigated, after diluting the same, by the 
addition of an equal amount of pure distilled 
water, using strong ammonia water for the pur¬ 
pose. To the solution, so neutralized, add one- 
thirtieth of the amount of the same of hydro¬ 
gen peroxide, thus reducing any iron present 


66 


The Automobile Handbook 


to the ferric state. If a sample of this solution 
is rendered alkaline by the addition of a suffi¬ 
cient quantity of ammonia water, then, if iron 
is present, enough to amount to anything of 
great moment, from the battery point of view, 
a brownish red precipitate will form. A test 
for chlorine is as follows: 

Make a solution of nitrate of silver in the 
proportion of 20 grams of the same, in 1,000 
cubic centimeters of pure distilled water, and 
add a few drops of this solution to a small quan¬ 
tity of the electrolyte to be investigated; if 
chlorine is present the solution will turn white, 
owing to the formation of chloride of silver, 
which will precipitate out. 

A test for nitrates is as follows: In a test tube, 
holding 25 cubic centimeters of electrolyte to be 
tested, add 10 grams of ferrous sulphate; to 
this carefully add 10 cubic centimeters of chem- 
ieally-pure sulphuric acid by pouring the same 
slowly down the side of the tube; in the pres¬ 
ence of nitric acid, a brown solution will form 
between the electrolyte to be tested, and the 
concentrated solution of sulphuric acid. 

The presence of copper may be detected from 
the fact that when ammonia solution is added 
to electrolyte, a bluish-white precipitate will 
form. In testing for mercury, lime water, if it 
is added to electrolyte in which mercury is pres¬ 
ent will evolve a black precipitate. Testing for 
acetic acid is as follows: To a small quantity 
of the electrolyte to be tested, add enough am- 


The Automobile Handbook 67 

monia water to render the same neutral; ferric 
chloride added to this solution will cause the 
same to turn red in the presence of acetic acid 
and the solution will then bleach, provided 
hydrochloric acid is added, thus affording con¬ 
clusive proof of the presence of the undesired 
acetic acid. 



Section Through Storage Battery Used For Light¬ 
ing and Engine Starting 

Battery, Storage, Starting and Lighting 

Types. The foregoing description and instruc¬ 
tions relating to storage batteries apply equally 
well to ignition, starting and lighting types. 
The following rules include the standard bat¬ 
tery instructions adopted by the Society of 
Automobile Engineers for the installation and 





























68 The Automobile Handbook 

care of batteries used in connection with elec¬ 
tric lighting and starting systems. 

Batteries must be properly installed. Keep 
battery securely fastened in place. Battery 
must be accessible to facilitate regular adding 
of water to, and occasional testing of, solution. 
Battery compartment must be ventilated and 
drained, must keep out water, oil and dirt and 
must not afford opportunity for anything to be 
laid on top of battery. Battery should have 
free air space on all sides, should rest on cleats 
rather than on a solid bottom, and holding de¬ 
vices should grip case or case handles. A cover, 
cleat or bar pressing down on the cells or ter¬ 
minals must not be used. 

Keep battery and interior of battery compart¬ 
ment wiped clean and dry. Do not permit an 
open flame near the battery. Keep all small 
articles, especially of metal, out of and away 
from the battery. Keep terminals and connec¬ 
tions coated with vaseline or grease. If solu¬ 
tion has slopped or spilled, wipe off with waste 
wet with ammonia. 

Pure water must be added to all cells regu¬ 
larly and at sufficiently frequent intervals to 
keep the solution at proper height. Add water 
until solution is level with inside cover. Never 
let solution get below top of plates. Plugs must 
be removed to add water, then replaced and 
screwed on after filling. The battery should 
preferably be inspected and filled with water 
once every week in warm weather and once 


The Automobile Handbook 69 

every two weeks in cold weather. Do not use 
acid or electrolyte, only pure water. Do not use 
any water known to contain even small quan ¬ 
tities of salts of any kind. Distilled water, 
melted artificial ice or fresh rain water are 
recommended. Use only a clean metallic vessel 
for handling or storing water. Add water regu¬ 
larly, although the battery may seem to work all 
right without it. 

The best way to ascertain the condition of 
the battery is to test the specific gravity (den¬ 
sity) of the solution in each cell with a hydrom¬ 
eter. This should be done regularly. A con¬ 
venient time is w T hen adding water, but the 
reading should be taken before, rather than 
after, adding water. A reliable specific gravity 
test cannot be made after adding water and 
before it has been mixed by charging the bat¬ 
tery or running the car. 

To take a reading insert the end of the rub¬ 
ber tube in the cell. Squeeze and then slowly 
release the rubber bulb, drawing up electrolyte 
from the cell until the hydrometer floats. The 
reading on the graduated stem of the hydrom¬ 
eter at the point where it emerges from the 
solution is the specific gravity of the electro¬ 
lyte. After testing, the electrolyte must always 
be returned to the cell from which it was 
drawn. The gravity reading is expressed in 
“points,’’ thus the difference between 1.250 
and 1.275 is 25 points. 

When all cells are in good order, the gravity 


TO The Automobile Handbook 

will test about the same (within 25 points) in 
all. Gravity above 1.200 indicates battery more 
than half charged. Gravity below 1.200, but 
above 1.150, indicates battery less than half 
charged. When the battery is found to be half 
discharged, use the lamps sparingly until the 
gravity is restored to at least 1.250. If by 
using the lamps sparingly, the battery does not 
come back to condition, there is trouble in the 
wiring or generator system which should be 
investigated and remedied immediately. Grav¬ 
ity below 1.150 indicates battery completely 
discharged or “run down.” A run down bat¬ 
tery is always the result of lack of charge or 
waste of current. If, after having been fully 
charged, the battery soon runs down again, 
there is trouble somewhere in the system which 
should be located and corrected. Putting acid 
or electrolyte into the cells to bring up specific 
gravity can do no good and may do great harm. 
Acid or electrolyte should never be put into 
the battery except by an experienced battery 
man. 

Gravity in one cell markedly lower than in 
the other, especially if successive readings show 
the difference to be increasing, indicates that 
the cell is not in good order. If the cell regu¬ 
larly requires more water than the others, thus 
lowering the gravity, a leaky jar is indicated. 
Even a slow leak will rob a cell of all of its 
electrolyte in time and the leaky jar should im¬ 
mediately be replaced with a good one. If there 


The Automobile Handbook 71 

is no leak and the gravity is, or becomes, 50 to 
75 points below that in the other cells, a partial 
short circuit or other trouble within the cell is 
indicated. A partial short circuit, if neglected, 
may seriously injure the battery and should 
receive the prompt attention of a good battery 
repair man. 

A battery charge is complete when, with 
charging current flowing at the finish rate 
given on the battery plate, all cells are gassing 
(bubbling) freely and evenly and the gravity 
of all cells has known no further rise during one 
hour. The gravity of the solution in cells fully 
charged as above is between 1.275 and 1.300. 

If for any reason an extra charge is needed 
it may be accomplished by running the engine 
idle, or by using direct current from an out¬ 
side source. In charging from an outside source 
use direct current only. Limit the current to 
the proper rate in amperes by connecting a suit¬ 
able resistance in series with the battery. In¬ 
candescent lamps are convenient for this pur¬ 
pose. Connect the positive battery terminal 
(with red post, or marked P or +) to the posi¬ 
tive charging wire and negative to negative. 
If reversed, serious injury may result. Test 
charging wires for positive and negative with 
a voltmeter or by dipping the ends in a glass 
of water containing a few drops of electrolyte, 
when bubbles will form on the negative wire. 
When charging, start at the starting rate and 
continue the charge at this rate until the cells 


72 


The Automobile Handbook 


gas freely. Then continue the charge for six 
hours at the finish rate. The specific gravity 
at the end of the charge should read between 
1.275 and 1.300. If the specific gravity does 
not reach this point, continue the charge at the 
finish rate until the specific gravity stops ris¬ 
ing, which is an indication that the battery is 
fully charged. 

A battery which is to stand idle should first 
be fully charged. A battery not in active: 
service may be kept in condition for use by 
giving it a freshening charge at least once a 
month, but should preferably also be given a 
thorough charge after an idle period before it 
is replaced in service. Disconnect the leads 
from a battery that is not in service, so that it 
may not lose charge through any slight leak 
in car wiring. 


The Automobile Handbook 


73 


TABLE 4 


LOAD CAPACITIES OF ANNULAR BALL BEARINGS 

(New Departure at 600 rev. per minute) 
Single Row Bearings. 


Bearing Balls 

Cap. 

Bearing Balls 

Cap. 

* No. 

Diam. No. 

Lbs. • 

No. 

Diam. 

No. 

Lbs. 

200 

7/32 

7 

135 

208 

7/16 

14 

1095 

300 

1/4 

6 

205 

308 

19/32 

11 

1590 

201 

7/32 

7 

175 

408 

13/16 

9 

2440 

301 

9/32 

6 

290 

209 

7/16 

15 

1175 

202 

7/32 

8 

215 

309 

21/32 

12 

2120 

302 

5/16 

6 

360 

409 

7/8 

10 

3140 

203 

1/4 

8 

280 

210 

15/32 

15 

1350 

303 

11/32 

9 

435 

310 

23/32 

12 

2540 

403 

1/2 

8 

820 

410 

15/16 

10 

3585 

204 

9/32 

8 

390 

211 

1/2 

16 

1640 

304 

11/32 

10 

485 

311 

25/32 

12 

3000 

404 

9/16 

8 

1035 

411 

1 

10 

4100 

205 

5/16 

12 

480 

212 

17/32 

16 

1850 

305 

13/32 

11 

745 

312 

27/32 

12 

3500 

405 

5/8 

8 

1280 

412 

1 1/16 

10 

4625 

206 

11/32 

13 

630 

213 

9/16 

17 

2215 

306 

15/32 

11 

990 

313 

29/32 

12 

4045 

406 

11/16 

9 

1745 

413 

1 1/8 

10 

5190 

207 

13/32 

13 

880 

214 

19/32 

17 

2455 

307 

17/32 

11 

1275 

314 

31/32 

12 

4620 

407 

3/4 

9 

2075 

414 

1 1/4 

10 

6415 


Double Row Bearings. . 


300 

1/4 

8 

255 

311 

11/16 

11 

3690 

301 

1/4 

8 

360 

312 

3/4 

11 

4200 

302 

1/4 

10 

440 

313 

13/16 

11 

4825 

303 

5/16 

8 

515 

314 

7/8 

11 

5550 

304 

5/16 

9 

575 

315 

15/16 

11 

6400 

305 

3/8 

9 

1000 

316 

1 

12 

7200 

306 

7/16 

9 

1385 

317 

1 1/16 

12 

8200 

307 

1/2 

10 

1815 

318 

1 1/8 

12 

9100 

308 

17/32 

11 

2245 

319 

1 3/16 

12 

10000 

309 

9/16 

11 

2850 

320 

1 1/4 

12 

12000 

310 

5/8 

11 

3275 

321 

1 5/16 

12 

13400 


74 


The Automobile Handbook 


Bearings, Ball. Ball bearings may be broadly 
divided into three classes—thrust, cone and an¬ 
nular. Thrust bearings are those intended to 
sustain end thrust, and in them care must be 
exercised to see that the points of contact of 
the balls are exactly opposite, and that the 
grooves in which the balls run are formed to a 
sectional radius a little larger than that of the 
balls, thereby securing safe' and easy move¬ 
ment of the balls. These grooves must be de¬ 
signed not only to give smooth rolling contact, 
but so that a measurable area of the ball’s sur¬ 
face contacts with the race. It is also possible 
for a thrust bearing to act at the same time as 
a radial bearing, in which case, however, the 
four-point system must be used. In thrust bear¬ 
ings the balls are constantly under pressure and 
table 5 gives suitable loads for equal shaft diam¬ 
eters and revolutions for different sizes and 
numbers of balls: 


table 5 . 


Shaft 
Diameter, 
in inches. 

Allowable 

Load 

lbs. 

R.P.M. 

Number 

of 

Balls 

Ball 

Diameter 
in Inches 

2.55 

550 

500 

22 

% 

2.55 

1,000 

500 

15 

% 

2.55 

1,200 

500 

14 

11/16 

2.55 

1,300 

500 

13 

% 

2.55 

1,600 

500 

12 

% 

2.55 

—9 - 

1,800 

500 

10 

1 


The adjustable cone bearing, Fig. 39, has been 
used in millions of bicycles with excellent re¬ 
sults, but under large loads has been found in¬ 
adequate. A ball can roll freely only with op¬ 
posite points in contact, and every third or 









The Automobile Handbook 


75 


fourth point of contact involves more or less 
spinning, or sliding movement of the ball, which 
shortens its life, and the bearing must operate 
to the detriment of the contact surfaces. 

The third and great type of ball bearing is 
the so-called annular one intended for radial 
loads. It consists of three elements—two races 
and the balls. The new annular bearings re¬ 
quire no adjustment or fitting, and the rolling 
action of the balls takes place without interfer¬ 
ence of friction. A wonderful advantage of 
this bearing is that as high as 96 per cent of the 
space between the races can be filled with balls, 
the balls being introduced through filling lots 
whose size is a little less than the diameter of 
the balls to be introduced, so that the balls are 
forced between the two races under pressure 
and by virtue of the elasticity of the material. 
In the annular bearing but 30 per cent of the 
balls are under load at one time, and it is pos¬ 
sible for equal axle sizes and speeds to use dif¬ 
ferent dimensions and loading according to 
the size of the balls. Table 6 gives suitable 
loads for equal shaft diameter, and revolutions 
for various sizes, and numbers of balls. 


table 6 - 


Shaft 

Diam. 

inches 

Allowable 
load on 
Bearing 1 , lbs. 

R. P. M. 

No. of 
Balls 

Diam. of 
Balls, 
Inches 

3.14 1 

1,000 

500 

1 20 

% 

3.14 I 

1.300 

500 

21 


3.14 1 

2,500 

500 

1 32 

1 

3.14 1 

3,000 

1 500 

1 14 

It 5 * 

3.14 ! 

4.500 

1 500 

! 11 

1 * 









76 


The Automobile Handbook 


Annular ball bearings are also made with two 
rows of balls, and in the majority of them each 
ball is in a separate cage. Experiments have 
proven that, where the balls contact with one 
another, after a few years the friction results in 
grooves being worn in them. In Fig. 37 is shown 
the form of separator used in the F. & S. bear¬ 
ings. If in the application of this bearing it is 



Fig. 37 

F & S Bearing Separator 


necessary to sustain heavy axle loads, it is ab¬ 
solutely necessary to add an independent thrust 
bearing, or to employ a combination bearing 
which takes the place of bolt thrust and radial 
loads. 

Ball Bearings —Two in One. Figs. 38, 39, 
and 40 illustrate a ball bearing manufactured at 
Bristol, Conn., which owing to its dual ability as 

















The Automobile Handbook 


77 


as expressed by its name (“two in one”) is 
especially adapted to automobile service. Its 
makers claim that it is able to withstand radial 
or thrust loads, or any combination of the two, 
with the use of but a single bearing with its 
attendant simplicity of mounting. In order to 
bring about this result, two rows of balls are 
employed in staggered relation to one another, 
and the ball races are so arranged that the line 



Fig. 38 

Assembled Bearing Complete 


of pressure is either at an angle of 45 degrees 
or 60 degrees with the horizontal, when the axis 
of rotation of the bearing is in a horizontal 
plane. 

Figure 38 shows the permanent assembly of 
the bearing, sufficient metal being provided in 
the shell to permit of drawing the latter tightly 
over the cups. 




78 


The Automobile Handbook 


Figure 39 shows the various parts of this 
bearing, and Fig. 40 is a semi-sectional view 
showing the order of their assembly, from the 
shaft outward, as follows; the cone, the separa¬ 
tor, the two cups and the shell. It will be no¬ 
ticed that the line of pressure of the cone, cups, 



Fig. 39 


and balls is at an angle of 45 degrees with the 
horizontal, and this feature applies equally to 
both rows of balls, thus adapting the bearing 
to withstand a load from any angle. Two semi¬ 
circular races are turned in the cone to receive 
the balls, while the sheet metal separator is so 
stamped that the ball retaining notches are 










The Automobile Handbook 


79 


staggered with reference to each other. These 
openings are made slightly larger than the ball 
diameter, so that the contact between the ball 
and separator is said to be a point contact at* 
one end of the axis of rotation, while the weight 
by separator is carried on the balls at the top 
of the bearing. By maintaining the relative 
positions of the balls at all times, cross friction 



Fig. 40 

Sectional View of Bearing 


it is ^ claimed is entirely eliminated, while the 
friction introduced by the use of the separator 
is practically negligible. 

Ball Bearings—Lubrication of. Ball bear¬ 
ings must be so housed in as to retain lubricant 
and exclude dust, grit, etc. An impression that 
ball bearings will operate without lubricant is 
quite general. It is barely possible that abso¬ 
lutely true spheres might roll on absolutely 


80 


The Automobile Handbook 


true surfaces if both were made of materials 
that were absolutely inelastie, and therefore 
would remain true under load. But since such 
absolute perfection of the shape is not to be had, 
some means must be taken to provide and re¬ 
tain lubricant. 

Rust and acid must be kept out of ball bear¬ 
ings. Experience and most carefully conducted 
tests have proven that long life under load can 
be realized from ball bearings only when the 
surfaces are not only true, but are also highly 
polished and smooth. Roughness will be broken 
down and leave still greater roughness. Rust 
and acid will destroy originally true and smooth 
surfaces. Since not a few' lubricants contain 
free acids, care in their choice must be exercised. 
Plentiful lubrication and a properly closed 
mounting are safeguards against rust. 

In the lubrication of ball bearings it is advis¬ 
able to use vaseline; or, when a lubricant of 
greater body or stiffness is desired, to use a mix¬ 
ture of vaseline and some high-grade mineral 
grease. The grades known as semi-fluid are very 
well suited for this use ' and any combination 
may be used with success in such cases. 

Annular Ball Bearings. In the annular ball 
bearing, Fig. 42, a race of balls C is contained 
between an inner retainer A and an outer race 
B, there being grooves in the opposing surfaces 
of these to receive the balls. In a Hess-Bright 


The Automobile Handbook 81 

bearing of this type, as illustrated in Fig. 41, 
the entire space between the races C and B is 
not occupied by balls, but is utilized in different 
ways. In this only enough balls to make a half 
circle in the bearing are used, and these are 
spaced apart by means of small helical springs. 
These springs contain oil pads of felt, and are 
headed by sheet-metal discs that extend far 



Fig. 41 

Hess-Bright Bearing 


enough into the grooves to prevent sidewise dis¬ 
placement of the springs, without, however, 
producing any more than a negligible friction. 
Assembling this bearing one race is placed ec¬ 
centric to another race and the requisite num¬ 
ber of balls slipped into positions, after which 
the races are made concentric and the balls reg¬ 
ularly distributed. This done, the separating 
springs with lubricating means are installed. 



82 


The Automobile Handbook 


Once the springs are in place the tension of them 
is such as to make the bearing self-contained. 



It is not practicable to disassemble or repair 
the various forms of annular ball bearings in 
the ordinary shop. These forms are not adjust¬ 
able and are not designed to be taken apart. 
It is quite possible to reform the races and to 
insert new balls when the bearing is badly worn 
or scratched, but such work must be done with 
machinery and tools especially designed for 
handling it. Ball bearing repairs are handled 
by various companies who specialize on such 
work and it will always be advisable to com¬ 
municate with one of them. 

Bearings, Plain. The composition of metals 
for plain bearings is given under the heading 
Alloys. ” Plain bearings are used generally 
for connecting rod crank pins, wrist pins and 


The Automobile Handbook 83 

crank shaft bearings in automobiles. The 
material and dimensions are determined accord¬ 
ing to the pressure exerted on the bearing wnich 
is measured in pounds per square inch for the 
projected area of the bearing, this area being 
equal to the bearing diameter multiplied by its 
length. The maximum allowable pressure is 
one beyond which the oil film will not be main¬ 
tained, this in turn depending on the char¬ 
acteristics of the oil used and the method of 
introducing the lubricant between the bearing 
surfaces. 

Some of the generally accepted limits for 
maximum bearing pressures in automobile con¬ 
struction are as follows: For the crank shaft; 
front bearing 850 pounds, rear bearing 700 
pounds, center bearing 900 pounds. For con¬ 
necting rod lower end bearings 1400 pounds 
and for wrist pin bearings 2200 pounds. 

Plain bearings are held by steel journals and 
caps and the bearing proper, called the liner, 
may either be in one piece composed entirely of 
the bearing metal or made by applying a shell 
of the bearing metal inside of an outer shell 
of some stronger material such as steel or hard 
bronze. The halves of split bearings are held 
in proper relation by thin strips of metal called 
shims. 

Hard and Soft Bearings. There are two 
general classes of solid bearings, those which 
contain a large per cent of copper and a small 
amount of the softer metals; which are known 


84 


Tne Automobile Handooon 


as hard metals, as brass or bronze. Those which 
contain a large proportion of tiii or lead and a 
small per cent of copper are known as soft 
metals—as babbitt-metal, anti-friction metal and 
white metal. 

In some instances and under certain condi¬ 
tions it has been found that a good close-grained 
cast iron makes an excellent bearing metal. 
Being of a granular nature, it has the property 
of retaining the lubricant in place, even when 
highly polished and under great pressure, with 



Fig. 43 Fig. 44 

Types of Plain Bearings 


a low co-efficient of friction, but is too brittle 
to withstand severe shocks. 

Plain Bearings. Plain solid bearings are 
used on many parts of an automobile, particu¬ 
larly in the engine and transmission bearings, 
although ball and roller bearings are taking 
their place in many constructions. The major¬ 
ity of the cars use brass, bronze or babbitt-metal 
on the main and crankshaft bearings, while ball 
and roller bearings are used on the transmission 
and wheel bearings. A typical plain bearing is 
shown in Pig. 43, in which A is the journal made 
of steel, while the bearing members shown at 

















The Automobile Handbook 


85 


B. B, are made of either brass, bronze, or babbitt 
metal. Figures 44 and 45 show different types 
of connecting rod bearings. For plain-bear¬ 
ings, the shafts of which are continuously run¬ 
ning at a high rate of speed, such as motors 
and speed-change gears, the working pressure 



Fig. 45 

Solid Connecting Rod Bearing 

per square inch should not exceed 400 pounds. 
As the arc of contact or actual bearing surface 
of a journal bearing is' assumed as one-third of 
the circumference of the journal itself, the pres¬ 
sure per square inch upon a bearing is therefore 
equal to the total load upon the bearing, divided 












86 


The Automobile Handbook 


by the product of the diameter of the journal 
times the length of the bearing. 

Let D be the diameter of the journal or shaft 
at its bearing, and L the length of the bearing, 
if W be the total load or pressure upon the bear¬ 
ing and P the pressure in pounds per square 
inch of bearing surface, then 

W 

P =- 

DXL ' 

If the total load or pressure on the bearing 
be known and the diameter of the shaft given, 
then the proper length of the bearing will be 

W 

L —- 

DXP 

If the length of the bearing be known and 
other conditions as before given, then the proper 
diamf ter of the journal will be 

W 

D =-• 

PXL 

Adjustment of Plain Bearings. The halves 
of split plain bearings will require adjustment 
or re-fitting after a considerable period of use 
and wear. This adjustment may be made either 
by removing a part of the shims, by filing the 





The Automobile Handbook 


87 


side of the retaining cap or by scraping the 
inner surfaces of the liners. 

Shims are the thin metal pieces found 
between the halves of the bearing at each side. 
One shim should be taken out of each side of 
the bearing, the cap replaced and the holding 
bolts tightened. If the shaft still turns freely 
another pair of shims, one from each side, should 
be removed. This process should be continued 
until the shaft binds in the bearing. After 
this binding is secured, the cap should again 
be removed and one pair of thin shims replaced 
so that, when oiled, the shaft will turn freely, 
but without play. 

If no shims are used the adjustment may be 
made by placing the bearing cap in a vise and 
draw-filing straight across both edges with a 
fine toothed double-cut file. If the work is 
properly done each side of the cap will be 
lowered evenly with the other. Should the shaft 
bind after replacing the cap and tightening the 
bolts, two thin shims should be made and one 
placed on each side. 

The best fit will be secured by removing shims 
or filing and then finishing the fitting by scrap¬ 
ing the bearing to a good fit. With the cap and 
liner removed, some form of color, such as Prus¬ 
sian blue, should be applied in a thin even coat 
to the shaft surface. The cap should then be 
replaced and the bolts tightened. The shaft 
should now be turned once around and the cap 
removed. Wherever the color has been rubbed 


88 


The Automobile Handbook 


onto the inner surface of the bearing liner the 
liner metal should be removed by scraping the 
high spot or surface thus indicated. After scrap¬ 
ing, the shaft is again covered with the color, is 
turned once around and the process repeated 
until at least two thirds of the entire inner 
surface of the liner shows the color. 

The handle of the bearing scraper should be 
held rather loosely with the fingers of one hand 
and laid lengthwise of the bearing liner so that 
two edges of the scraper rest on the bearing 
metal. The scraper blade can then be lightly 
pressed against the liner metal with the fingers 
of the other hand, when, by moving the blade, 
a thin layer of metal can be removed. 

Bearing, Plain, Clearance for. In fitting plain 
bearings the following radial clearances should 
be allowed: 

Connecting rod lower end, .002". 

Connecting rod lower end, forked, .003". 
Crankshaft main bearings, .002" to .004". 

Piston pin bushings, .002". 

End play should be allowed as follows: 
Connecting rod lower end, .004". 

For main bearing that takes end thrust (rear or 
center) allow .004" to .006". 

For bearings next to one taking thrust allow 
.015" more than for the thrust bearing. 

For bearings second from one taking thrust, 
.030" more than for thrust bearing. 


The Automobile Handbook 


89 


Bearing, Roller. A form of bearing used in 
a large number of cars of all types is that 
known as the roller. This form is made in three 
distinct types, one of which is known as the 
taper roller, another one the solid straight 
roller, and the third one the flexible roller. 

The taper roller bearing. Fig. 46, is composed 
of an inner and outer race, the inner race being 



Taper Roller Bearing 

designed to fit over the shaft and the outer one 
being carried by the bearing housing. The 
outer surface of the inner race is conical in 
form and the inner surface of the outer race is 
of a form to correspond, that is, its internal 
diameter is smaller at one side than at the 
other. Between the two races is carried a series 
of steel rolls, each one of which is tapered so 
that it fits between, and bears along its entire 
length on both races. This forms a bearing of 
anti-friction qualities similar to the annular 
ball, with the exception that the contact be¬ 
tween the rolling members and their supports 



90 


The Automobile Handbook 


is a line rather than a point. It is customary 
to maintain a predetermined distance between 
the separate rolls by providing cages into 
which the rolls fit loosely. It will be seen that 
because of the tapered formation it would be 
impossible to press the inner race hard enough 
to cause it to pass completely through the outer 
race with the rolls in place, while in the other 
direction the inner race would drop out because 
of its own weight. This feature allows the 
tapered roller bearing to withstand a large 
amount of end thrust when this thrust is ap¬ 
plied on one side of the bearing only. 


Fig. 47 

Straight Solid Roller Bearing 



Roller bearings are made of an inner and 
outer race with both surfaces of each race truly 
cylindrical, Fig. 47, and between these races is 
carried a series of straight cylindrical rolls. 
With plain rolls in use, the bearing will not 
withstand any end thrust because of the fact 
that the races and rollers will move freely over 



Fig. 48 

Hyatt Self-Oiling Self-Contained Roller Bearing 


The Automobile Handbook 


91 











92 


The Automobile Handbook 


each other in the direction of their axes. When 
it is desired to have this type of bearing with¬ 
stand a thrust load, one or' both of the races 
must be made with either a ridge or a groove 
at or near one edge and the rolls must then 
have a corresponding ridge or groove to en¬ 
gage the race. 

The flexible roller bearing is made by the 
Hyatt Roller Bearing Co. and consists of two 
races, each of which is tubular or cylindrical 
in form, and between these races is carried a 
series of rollers, as in other types previously 
described, differing in that the rolls are formed 
from a piece of comparatively thin flat steel 
twisted into a spiral. It is from the springiness 
of this form of spiral roller that the bearing 
takes its name, “Flexible.’’ 

The load capacities of Hyatt roller bearings 
in sizes having the same outside dimensions as 
annular ball bearings of the same number are 
as follows at 500 revolutions per minute: 


Bearing- Bearing Bearing 

Number Pounds Number Pounds Number Pounds 


307 

1,855 

312 

4,750 

317 

10,400 

308 

2,050 

313 

5,570 

318 

11,000 

309 

2,520 

314 6,900 

319 

12,300 

310 

3,450 

315 

7,920 

320 

14,200 

311 

4,170 

316 

8,775 



The Automobile Handbook 93 

Bendix Drive. The Bendix drive, Fig. 49, 
consists of a solid or hollow shaft having screw 
threads on the outside, and a hollow gear hav¬ 
ing screw threads on the inside, so that the 
gear screws on the shaft like a nut on a bolt. 
A circular weight is fastened to the gear, and 
is slightly out of balance. A coil spring con¬ 
nects the electric motor shaft and the hollow 
screw shaft. 





Fig. 49 

Starting Motor With Bendix Drive 
When the electric motor starts it drives 
through the spring and turns the screw shaft. 
Because of the weight, the gear is too heavy to 
turn with the screw shaft, and because the 
gear does not turn it must move along the 
screw shaft (just the same &s if you turned a 
bolt having a nut on it, and kept holding the 
nut with your fingers to keep it from turning 
so that it would be screwed along the bolt). 
After the screw gear has moved along the 
screw shaft and engages with the flywheel gear 
it then keeps on moving along until it reaches 



94 


The Automobile Handbook 


the stop at the end of the screw shaft. The 
two gears then are fully meshed, and it is obvi¬ 
ous that when the screw gear has reached the 
stop it cannot move any farther, and it then 
must turn with the screw shaft. At this par¬ 
ticular moment the screw shaft and electric 
motor are revolving at a great speed, and this 
great blow and the power of the electric motor 
are both taken through the coil spring. The 
spring keeps coiling until all this power has 
been applied to the flywheel gear and the en¬ 
gine starts turning. 

As soon as the engine starts exploding and 
runs under its own power, the flywheel of 
course turns much faster than it was cranked 
by the starter. Because it is now turning so 
much faster it increases the speed of the screw 
gear so that the latter runs faster than the 
screw shaft on which it is mounted. It is there¬ 
fore plain that if the screw gear runs faster 
than the screw shaft, that it will be screwed 
on the threads of the shaft (like a nut on a bolt) 
until it has been screwed out of mesh with the 
flywheel gear. This demeshing movement is 
entirely automatic and eliminates the use of 
an overrunning clutch. And now that the 
screw gear is out of mesh it is natural to sup¬ 
pose if the electric motor keeps running that 
the gear will be automatically screwed right 
back into the mesh with the flywheel gear. But 
the unbalanced weight on the screw gear per- 


The Automobile Handbook 


95 


forms its automatic function. That is, being 
slightly out of balance, the weight twists or. 
cocks the screw gear so that it clutches and 
binds on the screw shaft and turns with it. This 
automatic clutching is all due to the centrifugal 
force of the unbalanced weight. 

When the electric motor stops running, the 
screw gear has been fully screwed away from 
the flywheel gear, and it remains in that re¬ 
tarded position until it is again required to 
start the engine. 

The screw shaft should never be oiled or 
lubricated. It is not necessary and, in fact, 
the screw gear works to the best advantage 
when the screw shaft is dry. 

Through accident or otherwise, should the 
flywheel ever be entirely exposed and unpro¬ 
tected, and should the gear tend to stick on 
the shaft, it may then be necessary to clean 
the screw. 

The teeth on the screw gear and flywheel are 
chamfered or pointed on only one side to make 
the meshing natural and easy. However, should 
the teeth meet, end to end, the screw shaft 
itself is designed to move automatically back¬ 
wards, against and compress the coil spring. 
This gives the screw gear time enough to turn 
and enter the flywheel gear. Should sticking 
of gears ever occur, they can be released by 
throwing in the clutch and moving the car. 
Such trouble would be due to incorrect cham- 


96 


The -Automobile Handbook 


fering or inaccurate alignment of the gears. 
Also it might be due to the binding of the drive 
parts and prevent compressing and proper func¬ 
tioning. Such defects should be corrected. 

If while the engine is running, the electric 
motor should be accidentally started, the screw 
gear will of course screw over against the turn¬ 
ing flywheel gear. But instead of the clashing 
and smashing of gears that might be expected 
there is no damage whatsoever, as the gears 
simply touch once. This is because the flywheel 
gear will speed up the screw gear, and thus 
automatically screw it away. The turning screw 
gear will then automatically clutch and bind 
on the screw shaft, in exactly the same manner 
as when it is cranking and has been demeshed 
when the engine starts exploding. 

Bodies. In the construction of automobile 
bodies the sills are made strong, and the super¬ 
work is rendered independent of the actual 
structural strains. Wood is generally used in 
the framing, although it is sometimes replaced 
by cast aluminum. 

When wood is used for framing, sheet alumi¬ 
num, steel and thin layers of wood are em¬ 
ployed. The aluminum is laid on a form and 
beaten to the shape required for the panel. The 
steel sheets are die formed, while the wood is 
made flexible in order that it may be bent to 
its proper shape when fastened to the body. In 
order to have the car of light weight, all body 
builders use the lightest materials possible in 


The Automobile Handbook 


97 


the construction of that portion* which lies above 
the chassis. 

When aluminum is used in the panels and 
for facings, care must be exercised to prevent 
water from creeping in between the metal and 
the framing, because water causes an electro¬ 
lytic action on the aluminum plates. To prevent 
the oxidation of sheet steel, the plates are either 
coated with aluminum or zinc, or they are given 
a priming coat of paint on the inside. 

As a general thing, putty is not used in the 
construction of bodies, as there are few joints 
which require it. In the very best body paint¬ 
ing twenty coats are used before the paint as¬ 
sumes its proper finish. The first coat,-or prim¬ 
ing coat, generally consists of pure white lead 
mixed in oil. After that the second priming coat 
is given to it, and from then on the number 
of coats of rough paint will depend upon the 
nature of the surface and the degree of finish. 
For a very fine finish, the last coats consist of 
varnish, but when wagon finish is desired, the 
last coats consist of paint. 

Finishers must take into account the fact that 
all cars are more or less abused in service, and 
it is to be expected that the magnificently 
equipped limousine will have a somewhat finer 
finish than the hard used touring car. 

Classification of Bodies. Besides being 
classified according to the type of gasoline en¬ 
gine, methods of transmission, number of cyl¬ 
inders, etc., automobiles are also classified ac- 


98 


The Automobile Handbook 


cording to the type of body which is mounted 
on the chassis. While there are a considerable 
number of names which are given to the same 
types of pleasure automobiles, they may be gen* 
erally classified as runabouts, roadsters, toura- 
bouts, touring cars, town cars or taxicabs, lan- 
daulets, limousines and semi-limousines. Elec¬ 
tric automobiles are generally divided into 
coupes, brougham, stanhopes, runabouts, phae¬ 
tons, etc. Steam cars- follow* the same general 
classification as gasoline machines. Commer¬ 
cial vehicles may be classified as taxicabs, deliv¬ 
ery wagons, trucks, busses, wagonettes, ambft- 
lances, patrol wagons and other forms for fire 
service. 

Commercial Vehicles. In the commercial 
vehicle field steam, electric and gasoline ma¬ 
chines are used. Electric vehicles are used for 
certain purposes, from heavy trucks to light 
delivery wagons, usually only for short dis¬ 
tances. Steam power is not at present being 
used to any extent for heavy trucks, while} 
the gasoline commercial is used for trucks, 
business wagons and quick deliveries. 

The commercial vehicle may be classed as 
follows: Taxicabs, general delivery, light trucks, 
heavy trucks, coal wagons, sight-seeing cars, 
busses, ambulances and particular other types 
for special purposes. 

Since, for general purposes, the speed of com¬ 
mercial vehicles is small, they are not neces¬ 
sarily equipped with high power, as a heavy 


The Automobile Handbook 99 

car, which would travel at a high speed, would 
be apt to be dangerous. The speeds obtainable 
range on an average between twenty miles per 
hour for delivery wagons, to five miles per hour 
for heavy trucks. 

While there are many distinct types of car 
boc(ies, there are more names in use than there 
are bodies, because different makers often apply 
different names to the same type of body, and 
often list a certain type of body under a name 
different from the one ordinarily accepted. This 
practice makes it difficult to state positively that 
a certain type of body will be called by a given 
name by a maker although that particular body 
is of its own distinctive type regardless of the 
name applied in the catalogues. 

Bodies may be classified according to the num¬ 
ber of persons carried, whether they are wholly 
or partly enclosed and according to the purpose 



Fig. 50 

Five-Passenger Touring Car 
for which they are designed. None of these 
divisions is very satisfactory, because some types 





100 


The Automobile Handbook 


would appear in more than one division. The 
following definitions are those generally ac¬ 
cepted. 

Touring Car. This is an open car, Figs. 50 
and 51, for general purposes which may seat 
four, five, six or seven persons, including the 
driver. It has sides and doors, but when pro¬ 
tection from the weather is desired the operator 
uses a folding top and curtains. 



Fig. 51 

Seating Arrangement in Four-Passenger Car 

A touring car seating five is called a five-pas¬ 
senger touring car, one seating seven is called a 
seven-passenger touring car, and so on for any 
number of passengers. The rear compartment of 
a touring car is called a tonneau, the front com¬ 
partment is called the driver’s compartment. 

Close-Coupled or Toy Tonneau. A four- 
passenger touring car with the rear seat brought 
well forward is sometimes called by one of these 
names. 

Torpedo. This is a touring car having, the 
body as small and low as possible while seating 












The Automobile Handbook 


101 


the number of passengers desired. The body is 
of a form that offers the least resistance to wind 
pressure and is called “stream line” in shape. 

Runabout. This is an open body seating two 
passengers, mounted on a comparatively small, 
light or low powered chassis for use fn town and 
-city travel and short country trips. 



Fig. 52 

Two-Passenger Roadster 

Roadster. This is also an open body, Fig. 52, 
seating two passengers, but mounted on a chassis 
whose size, weight and power fits it for heavy 
work and long distance touring. 

Speedster or Raceabout. This is a powerful 
chassis carrying small, light seats for two pas¬ 
sengers and designed for high speed work. The 
body is made as small and light as possible with 
“bucket” seats, floor, dash, gasoline and oil 
tanks, but no sides or doors, and in most cases 
without a top. 

Limousine. This is a type of body, Fig. 53, 
used mostly for town and city driving in bad 
weather or during the cold season. 



102 


The Automobile Handbook 



It seats four, five, six or seven persons in addi¬ 
tion to the driver. It has a permanent top and 
the rear compartment is entirely enclosed and 
has full doors. The driver’s compartment is di- 


Fig. 53 

Limousine Body 

vided from the rear by a partition and this com¬ 
partment w only partly enclosed. 

Berline or Berlin. This type is exactly like 
the limousine except that the driver’s compart¬ 
ment is fully enclosed and has full doors. 

Sedan. This body is like the Berline, that is 
to say, fully enclosed, but there is no partition 
between the driver’s and rear compartment. 

Landaulet or Landau. This is a limousine 
which has the rear half of the passenger com¬ 
partment closed with a top that is rigid when 
raised but that lets down like those tops of closed 
€*> nrmges in common use. 








The Automobile Handbook 103 

Town Car. This type has the rear compart¬ 
ment entirely enclosed with full doors, and seats 
four or five persons in this part of the car. The 
driver’s compartment is open, the same as in a 
touring car. The driver may be protected by a 
small canopy extending forward from the en-" 
closed portion. 



Fig. 54 
Coupe 

Coupe. This type of body, Fig. 54, is entirely 
enclosed and has full doors. It may seat two, 
three or four passengers in the enclosed part, 
the driver being one of these. It is mounted on 
a roadster chassis and bears the same relation to 
the roadster that the Sedan bears to the touring 
car. 

Convertible Coupe or Sedan. These bodies 
are built in such a way that they give exactly 
ihe same appearance as a regular Coupe or Sedan 
from either the outside or inside. The upper 






104 


The Automobile Handbook 


portion is removable so that the Coupe or Sedan 
is converted into a roadster or touring car, de¬ 
pending on the arrangement and number of 
passengers carried. 

Cabriolet or Couplet. A convertible coupe 
may be called by either one of these names, both 
meaning the same thing. 

Taxicab. A car used as a public vehicle and 
being for hire according to certain designated 
rates of fare is called a taxicab. It is fitted with 
a “taximeter ’ 9 which records the distance trav¬ 
eled and the time spent in waiting, and automat- 
ally computes and indicates the fare to be paid. 

Taxicabs may be made from limousines, lan- 
daulets or town cars, the landaulet being the 
type most generally used. 

Commercial Car Bodies. These types include 
those used for carrying merchandise and also 
those used for carrying passengers as a business. 
Commercial car bodies may be designated accord¬ 
ing^ the type of construction, the class of work 
to be handled or the weight to be carried. 

Truck Bodies. These include the express, 
platform, stake and panel types, and also many 
special designs. Truck bodies are usually made 
from designs prepared for each individual job 
and according to the customer’s requirements, 
except in the lower priced cars. 

Passenger Bodies. These include taxicabs, 
sight seeing cars, carrying from eight to twenty 
persons, and closed bodies suitable for carrying 
passengers and baggage in interurban work. 


BRAKES 


The Automobile Handbook 


105 



Brakes. A brake is a mechanism which is 
a necessarv t>q.rt of the machinery of an auto¬ 
mobile and enables the operator by exerting a 
slight amount of force on a lever to reduce the 































106 


The Automobile Handbook 


momentum of the moving car. Brakes used on 
automobiles may be divided into three classes: 
Hub or rear wheel brakes, transmission and 
differential gear brakes. Brakes have also been 
applied to the tires of the rear wheels, but 
have proved unsatisfactory and have been aban¬ 
doned. The forms of brakes in use are single, 
or double-acting, foot or hand operated, and of 
the band, block or expanding ring types. 

Figure 55, at A, B and C, shows three forms 
of the simplest type of single-acting band-brake. 
This type of brake can only be operated success¬ 
fully with the brake wheel running in one 
direction only, which is indicated by the arrows 
in the drawing. If the brakes be operated in 
the reverse direction to that indicated by the 
arrows the result will be to jerk the lever or 
pedal out of the control of the operator of the 
car. 

The three forms of band-brakes shown at A, 
B and C are all of the same principle, the differ¬ 
ence being in the location of the fixed end of 
the brake-band and the shape of the operating 
lever. Type D is a form of double acting block- 
brake, which is designed with a view to elimi¬ 
nate any strain or side thrust upon the shaft of 
the brake wheel which may be caused by the 
braking action of the device. Types E, G and 
H are three types of double acting band-brakes, 
in which the brake may be applied with the 
brake wheel running in either direction. 

Type F is a form of double acting block-brake, 


The Automobile Handbook 107 

in which the right hand ends of the brake-shoe 
arms are pivoted to stationary supports, and 
the left hand ends connected together by means 
of a link and bell-crank lever as shown in the 
drawing. 



In Figure 56 a form of double acting block- 
brake I is shown, which is extremely powerful 
on account of its peculiar construction, in that 
is has a double leverage upon the brake wheel, 
which may be readily seen by reference to the 
drawing. Types J and K are of the form known 

















108 


The Automobile Handbook 


as internal brakes and of the expanding ring 
type, the brakes operating upon the inner sur¬ 
face or periphery of the brake wheel, instead 
of the outside. They are known as hub brakes, 
being usually attached to the hubs of the rear 
wheels of the car. Type L shows a form of 
block-brake in which the pivoted brake arms 
are drawn together by the eccentric located on 
the brake lever shaft. When the lever is re- 



Fig. 57 


leased the brake-shoe arms are forced apart by 
the action of the coil spring between the upper 
ends of the arms. 

Expanding Brake. In the internally expand¬ 
ing brake, Figure 57, a hollow metal drum or 
pulley D is carried upon some continuously 
revolving portion of the car mechanism, and 
within this drum are supported two metallic 
shoes B B, which conform in shape to the inside 




The Automobile Handbook 


109 


surface of the drum by means of a spring, S S. 
The shoes are capable of being strongly pressed 
against the revolving inner surface of the drum 
by means of a cam or toggle arrangement, T, 
operated through a wire rope or metal rod, R, 
from the operator’s lever or pedal. It is im¬ 
portant that brakes of both these types should 
have their bands or shoes so arranged that an 
equal frictional effect is produced upon their 
drums for a given force applied by the operator, 



whether the vehicle is running forward or back¬ 
ward. A brake so arranged is said to be double 
acting. 

Brake Linings. For expanding brakes, metal 
shoes have become standard, owing to the prac¬ 
ticability of maintaining proper lubrication be¬ 
tween the frictional surfaces. In external 
brakes the metal band is provided with some 
form of nonmetallic lining that forms the brak¬ 
ing surface applied to the drum. The reason 





110 


The Automobile Handbook 


for this is that it is practically impossible to 
properly lubricate an external brake. Various 
kinds of material, viz., leather fabric, asbestos, 
vulcanized fibre and camel’s hair belting, are 
used for lining external brake bands. A ma¬ 
terial which is used for this purpose must have 
great resisting powers, a constant co-efficient 
of friction, even in the presence of oil and 
water, and it must have the ability to resist 
the influence of heat due to the brake’s action. 
In practice it has been found that leather lined 
brakes burn out, and fibre linings become brittle 
and cannot be depended upon, so that inorganic 
materials, which cannot be carbonized, such as 
asbestos fibre, are widely used. Asbestos fibre 
may be readily woven into a fabric which an¬ 
swers this requirement, but when used by itself 
its strength is not sufficient. When, however, 
it is woven over a metal wire gauze foundation 
it appears to have the necessary stability to 
withstand very severe service, and this is the 
method employed in manufacturing the incom¬ 
bustible brake linings which are being used. 

Cork is the bark of the cork tree, and is the 
lightest known solid. Its weight is one-eleventli 
of aluminum, and one-thirtieth of cast-iron. It 
has a very high co-efficient of friction, and is 
not affected by many of the conditions which 
seriously impair the efficiency of other sub¬ 
stances. 

Cork possesses qualities which distinguish it 
from all other solids, namely, its power of alter- 


The Automobile Handbook 


111 


ing its volume to a very marked degree in con¬ 
sequence of a change of pressure. It consists, 
practically of an aggregation of minute air ves¬ 
sels, having thin, water-tight, and very strong 
walls, hence, if compressed, the resistance to 
compression rises in a manner more like the re¬ 
sistance of a gas, for instance, than to that of 
an elastic solid, such as a spring. The elasticity 
of cork has a wide range and is very persistent. 
It is this elasticity which makes it valuable when 
used as an insert in a metal shoe. Cork is of 
rather a brittle nature, though extremely strong, 
and for that reason it cannot be used in the form 
of a lining or facing. The method of appli¬ 
cation is to insert corks in holes in the brake 
provided for the purpose. Cork is not particu¬ 
larly affecfed by heat or oil, and will largely in¬ 
crease the efficiency in any application to a 
brake or clutch. 

Where metal-to-metal surfaces, with or with¬ 
out cork inserts, are used, the surfaces are usu¬ 
ally of different materials. The most common 
material for drums in all cases is steel, but that 
of shoes is either malleable cast iron, brass or a 
bronze. Different metals make a better wear¬ 
ing surface, and some combinations will have a 
higher degree of friction adhesion than others. 

In the selection of material for brake linings, 
the co-efficient of friction is an important factor 
to be considered. Table 7 gives the relative 
values existing in combinations of different 
materials. 


112 


The Automobile Handbook 


table 7. 

Material— 

Metal to Wood. 

Metal to Fibre.. 

Metal to Leather . 

Metal to Metal . 

Metal to Cork. 


Co-efficient 
of friction 
0.25 to 0.50 
0.27 to 0.60 
0.30 to 0.60 
0.15 to 0.30 
0.36 to 0.65 


Equalizers. In connection with all brakes 
which are used in pairs, some method is used to 
equalize the pressure of the brake handle or foot 
pedal so'that the same pressure will be applied 



to both brakes. If the power is not equally ap¬ 
plied to each brake, side slip or “skidding” will 
result. 

The different methods of equalizing brakes are 
shown in Figs. 59, 60, 61 and 62, the majority of 
cars using what is known as the floating lever 
type, the cable arrangement being used only on 
several makes of cars. The floating lever type 
































The Automobile Handbook 113 

of equalizer is illustrated in Fig. 59. L is the 
floating lever, connected at its central point to 
the brake lever, or pedal by means of rod R. 
The ends of lever L are connected to the brakes 
B, B, by means of the brake rods C and D. 
When rod R is drawn forward, lever L draws 
rods C and D forward thus giving an equal pres¬ 
sure on the hub brakes. 

Fig. 60 shows another type of floating lever 
equalizer. Shaft S connects to the brakes by 



means of rocker arms located just outside the 
frame. Two rocker arms, C and D are con¬ 
nected to shaft S, and to the equalizing lever L 
by means of rods E and F. In some cases the 
equalizing lever is located outside of the frame. 
It then takes the form shown in Fig. 61, in 
which L is the lever that equalizes the pressure 
on both brakes connected to shaft S. Fig. 62 
shows the arrangement of the cord equalizer. 
Shaft S is connected to the two brakes, one at 











114 


The Automobile Handbook 


each end, and it has two rockers, or cranks E 
and F attached to it. Parallel to S is another 
shaft C, which carries a grooved roller R. A 
cable is connected to crank E, carried over R, 
and then passing back, is connected to crank F. 
When R is moved in the direction of the arrow, 
by the brake lever, the cord distributes the ten¬ 
sion between E and F, and as a consequence the 
brake also. This type is much cheaper than 



Fig. 61 

^ Equalizer Lever Outside the Frame 





































The Automobile Handbook 115 

Brazing. Many workmen labor under the im¬ 
pression that a brazing job cannot be done un¬ 
less the parts are a loose fit, in order, as they 
say, to allow the brazing material to enter and 
form a bond. The result is, when they do the 
work, the parts are a very loose fit, with accen¬ 
tuated shearing tendencies in the section of the 
bra sing material, and if the brazing happens to 
be poorly done, the result is anything but good, 
since, in the absence of brazing, there is not 
ev^n a good mechanical bond. 

A good mechanical bond is possible to procure 
without, in any way, interfering with the braz¬ 
ing process, since the parts, if they are well 
fluxed, will take a coat of brazing material, even 
•when the recess is but a thousandth or two. In 
brazing, if the -work is to be up to a sufficient 
standard to use in steering gear, it is necessary 
to clean and brighten the surfaces in a most 
thorough manner. This will best follow by me¬ 
chanical scraping rather than by dipping in 
some corroding material. Dipping may be of 
value as a preliminary, but a file, and scraper, 
in the hands of a man of competence, will go a 
long ways toward success. 

When the parts are well brightened, and the 
grease is thoroughly removed, by the use of 
soda water, benzine, or equally good solvents, 
it remains to flax the parts with borax, and 
then apply the heat, either by a forge or from a 
special form of brazing torch which uses gaso¬ 
line, kerosene, or other fuel oil, to pro¬ 
duce the necessary heat. All forms of burn- 


116 


The Automobile Handbook 


ers have means of adjusting the flame, and 
two or more burners are usually placed 
in such position that their flames strike 
the work. Torches are similar to the 
Bunsen burner; if fire brick, or clay, is used to 
build up around the parts, the heating process 
will be attended with less difficulty, and the work 
will be better at the finish. A rather hard braz¬ 
ing material may be used. This may be pur¬ 
chased ready for use, and there is no reason at 
all why a motorist of even slight skill cannot 
make a good job of brazing. 

Brazing Methods. The brazing flame must 
be so adjusted that no soot is deposited on the 
work and care should be exercised that no for¬ 
eign matter of any kind enters between the sur¬ 
faces to be joined. 

But a single tool is required in brazing, this 
being a spatula formed by flattening one end 
of a steel rod which is from one-quarter to 
three-eighths inch in diameter. This spatula is 
used for placing the spelter, or brazing metal, 
on the work and for handling the flux. 

Spelter, the metal used to make the joint, is 
variously composed of alloys containing copper, 
zinc, tin and antimony. Hard spelter, melting 
at about 1650° Fahrenheit is used with cast or 
malleable iron and with steel. A metal suitable 
for joining copper contains nearly equal parts 
of copper and zinc and melts at about 1400°. 
For fastening brass to iron and copper and for 
handling large pieces of brass to brass, a still 


The Automobile Handbook 117 

softer spelter is used, containing two-thirds tin 
and one-third antimony. 

The most generally used flux is pure calcined 
borax powder, this powder, mixed with about 
15% of powdered sal ammoniac, making a satis¬ 
factory agent. 

The surfaces to be brazed are thoroughly 
cleaned as already described and the parts are 
then placed in the relation to each other that 
they are to finally occupy. The work is then 
placed so that the melted spelter and flux will 
flow down into the joint and the work is braced 
or clamped in this position. It is advisable to 
place fire brick around the work to protect it 
from cooling draughts of air. The work is then 
well covered with flux, which is made into a 
paste with water, and the heat is applied until 
the flux boils and runs over the surfaces. 
Spelter is then placed in such a position that it 
will run into the joint and the heat is continued 
or increased until the spelter flows between the 
surfaces of the joint. The flame should surround 
the work so that air is excluded as far as pos¬ 
sible. 

Care should be exercised to avoid softening 
the metal in the work by too much heat, and 
when brazing two different metals together, the 
flame should be directed only on the one melting 
at the higher temperature, allowing the. other 
metal to receive its heat from the one in the 
flame. 

As soon as the spelter melts and flows, the 


118 


The Automobile Handbook 


heat should be removed. Should the spelter 
form into small globules instead of flowing, tap¬ 
ping the work will usually overcome the diffi¬ 
culty. If tapping does not produce the desired 
result, more flux, in dry form, may be added. 

Carbon Deposit, Removal of. The outfit 
consists of a high pressure cylinder of oxygen 
gas with a reducing valve, pressure gauge, 
length of rubber hose, a shut off valve and a tube 
of flexible copper for introduction into the com¬ 
bustion space of the cylinders. 

The shut off valve from the gasoline tank on 
the car should be closed and the engine run 
until it stops because of the exhaustion of the 
supply of gasoline in the lines and carburetor 
float bowl. 

If the engine has ‘ ‘ T ’ ’ or “ L ’ ’ head cylinders, 
one of the valve caps should be removed. If 
the cylinders have overhead valves, remove the 
spark plug. In any case, should any spark 
plug then remain in the cylinder, it should be 
removed and replaced, during the operation, 
with an old one. 

Having selected the cylinder to be cleaned 
first, raise its piston to the top center following 
the compression stroke so that both valves are 
tightly closed. In case the carbon has been 
burned hard the interior of the combustion 
space should then be wiped with a swab wet 
with kerosene until all of the carbon has been 
moistened. 

The valve on the high pressure oxygen cylin- 


The Automobile Handbook 


119 


der should then be opened, the shut off valve on 
the torch should also be opened, and the reduc¬ 
ing valve handle screwed in until the low pres¬ 
sure gauge shows from two to three pounds. 
Then close the shut off cock and insert the end 
of the flexible tube into the cylinder. 

Now open the shut off valve and introduce a 
lighted match or taper into the cylinder until 
the carbon starts to burn. Manipulate the end 
of the tube inside of the cylinder until all sur¬ 
faces have been reached, taking special care 
with the valve pockets and other recesses. When 
the flame will no longer continue, despite move¬ 
ment of the tube, the burning has been com¬ 
pleted. 

In case the engine or dust pan is dirty or oily 
it will be well to protect the opening into the 
cylinder by means of sheets of asbestos or of 
thin sheet metal because there will probably 
be a considerable display of sparks which would 
ignite any exposed fuel or dirt which is oil 
soaked. It is also well to have a reliable fire 
extinguisher convenient to the hand of the 
operator during the operation. 

Having completed the burning, the combus¬ 
tion space should be blown out with a blast of 
air from a compressor or from a hand bellows, 
thus removing the reminder of fine, dry carbon 
dust. 

Lubricating oil is charged with the crime of 
depositing carbon on the surfaces of the com- 


120 


The Automobile Handbook 


bustion chamber, and this carbon in turn causes, 
“bucking,” and pre-ignition. It probably is true 
that inferior cylinder lubricating oil will de¬ 
posit carbon, to some extent, but the main trou¬ 
ble is from the gasoline which will not vaporize 
until it is allowed to contact with the hot cyl¬ 
inder walls, and this process of reducing the 
gasoline to vapor is bound to lead to a carbon 
deposit for the same reason that wood is 
“coked” if it is heated to a temperature of 
about 650 deg. C., provided the amount of air 
present is less than that which would cause 
complete combustion. 

Piston Head Scraper. In most engines the 
piston heads can be scraped clean of carbon 
without removing the pistons from the cylinders, 
by means of specially formed scrapers intro¬ 
duced through the opening over the valves, or 
through the spark plug holes when the latter 
are horizontal. The form and size of scraper 
will depend on the particular engine, but al¬ 
most any suitable form may be made from 5-16- 
inch steel tubing about 12 inches long hav¬ 
ing the ends hammered flat, and turned over at 
right angles in a vise. The ends are then 
filed straight, and sharp, and the shank of the 
scraper may be bent to right or left, if neces¬ 
sary, or left straight. Frequently two scrapers 
will be needed in order to use both right and 
left hand bends. The advantage of tubing for 
this purpose is that no blacksmith work is nec¬ 
essary. 


The Automobile Handbook 121 

Carburetors, Principles of. Internal combus¬ 
tion engines used for the propulsion of motor 
cars use gasoline for fuel in almost all cases. 
Experimenting is now going on in the endeavor 
to use kerosene or alcohol, and in some cases 
even lower grades of fuel. Gasoline and kero¬ 
sene are secured by heating crude petroleum 
until vapor is given off, and this vapor is passed 
through pipes that are kept cool enough to con¬ 
dense the vapor into a liquid. Alcohol is se¬ 
cured by the distillation of fermented -vege¬ 
table matter, and may be secured in almost 
any part of the country if suitable means for 
distillation were to be developed. 

Before the gasoline is ready to burn in the 
engine cylinders, it must be turned into a gas 
or vapor. If gasoline stands exposed to the air 
it will vaporize at a comparatively slow rate, 
but if ejected from a small opening in a fine 
stream it will turn to vapor and mix with air 
much more rapidly. It is always necessary to 
mix the gasoline vapor with air in certain pro¬ 
portions to make a combustible mixture. The 
instrument that turns the gasoline into a gas 
and then mixes the gas with air is called the 
carburetor and the process is called carbureting . 

Many forms of carburetors have been made 
and used, but all instruments now fitted are of 
the type known as automatic float feed. The 
spray nozzle is the small opening inside of the 
carburetor through which the liquid gasoline 
is drawn when it is to be made into a vapor. 


122 


The Automobile Handbook 


The nozzle opening is placed in a tube through 
which the air must pass on its way to the engine 
cylinders. See Fig. 63. One end of this tube 
is open to the outside air and the other end 
attaches to the piping that goes to the engine 
cylinders. The end open to the air is called 
the primary air intake. 



Fig. 63 


Float-Feed Carburetor Mixing Chamber and Air 
Valve. A, Spray Nozzle. B, Adjusting Needle 
Valve. C, Primary Air Intake. D, Auxiliary Air 
Valve. E, Air Valve Spring. F, Throttle Valve. 

When the piston travels away from the cylin¬ 
der head on the inlet stroke, the inlet valve 
opens and a cylinder full of mixture is drawn 
from the carburetor. The air to make the mix- 






The Automobile Handbook 123 

ture is drawn through the carburetor primary 
air intake and must pass by the nozzle opening. 
The gasoline is maintained at a height slightly 
below the nozzle opening, and the suction, or 
partial vacuum, of the incoming air causes, 
some of the gasoline to be drawn out of the 
nozzle so that its spray mixes with the air. 
This is the principle on which all modern car* 
buretors operate, but certain added features 
are necessary to compensate for the different 
conditions obtaining under different rates of 
car speed and engine load. 

The first difficulty that would be encountered 
with the simple form of carburetor just de¬ 
scribed would be that of a falling gasoline 
level in the nozzle as the fuel was drawn into 
the engine. This would finally result in a fail¬ 
ure of the fuel supply and stoppage of the 
engine. In actual practice, the gasoline from 
the car’s tank does not pass directly into the 
nozzle, but goes first into a small tank on the 
carburetor, which tank is called the float cham¬ 
ber. Of the two openings in this small tank, 
one goes to the gasoline supply and the other 
communicates with the carburetor nozzle. In¬ 
side of the float chamber is a piece of cork cov¬ 
ered with shellac or else a hollow metal cylin¬ 
der, either of which will float on the surface of 
whatever gasoline may be in the chamber. At 
the opening of the pipe that comes into the 
float chamber from the gasoline tank is a small 
valve, Fig. 64, operated by connections at- 


124 


The Automobile Handbook 


taclied to the float itself. When the float is 
low down in the chamber this valve is open; 
bat as the float rises on the surface of the liquid 
coming from the tank, it finally reaches a height 



E 

Fig. 64 

Carburetor Float Valve Mechanism. A, Float. B, 
Float Lever Pivot. C, Float Lever. D, Float 
Valve. E, Gasoline Inlet. 

at which the valve is closed, and it will there¬ 
fore be seen that the level of the liquid cannot 
rise above the point determined by the position 
of the float when the valve closes. When gaso¬ 
line is drawn from the float chamber, through 
the nozzle, the float falls with the fuel level 
until the valve is again opened, and by this 
repeated action the level is maintained constant. 

Other parts of the carburetor, such as the 
auxiliary air valve, are described in the follow¬ 
ing pages and the construction and adjustment 
of the well known makes are taken up. 










The Automobile Handbook 


125 


Almost any carburetor will give a reasonably 
good mixture through a limited range of action. 
Frequently, however, this range is found insuf¬ 
ficient for a particular engine. If right for low 
speeds, it is wrong for high speeds, and vice 
versa. 

The theory of carburetor action as regards 
the behavior of the gasoline jet under different 
air velocities is still only partially -understood, 
and has been the subject of a great deal of 
more or less blind theorizing, based in many 
cases on wholly inadequate data. 

A non-automatic spraying carburetor (i. e., a 
simple nozzle in an air tube) makes no mixture 
at all till the velocity of the air stream reaches 
a certain minimum. Beyond this point, the 
richness increases with the speed. Dilution 
from the auxiliary valve is therefore required 
only when the richness of the mixture exceeds 
the normal. At this point it should be remem¬ 
bered that, so far as the spray is concerned, 
there is no difference between a wide open throt¬ 
tle at slow engine speed (as for instance, up 
hill) and reduced throttle with high engine 
speed. The spraying action is concerned only 
with the velocity of the air past the nozzle be¬ 
fore the throttle is reached. 

Almost every carburetor is provided with the 
needle valve controlling the spray orifice. With 
this provision it is very easy to determine 
whether or not the carburetor is doing as well 
as it should at either low or high speed. For 


126 


The Automobile Handbook 


example, suppose we start with an adjust¬ 
ment known to be satisfactory for medium 
speeds. If the low speed performance is under 
suspicion, it is only necessary to increase the 
needle valve opening slightly to ascertain 
whether starting is thereby made easier, and a 
walking pace more smoothly maintained. If 
overheating results, reducing the needle open¬ 
ing will probably cure it. Similarly slight 
changes in the needle opening, without chang¬ 
ing any other adjustment, will determine 
whether or not the mixture is improved by 
less, or more gasoline at high speed. When the 
carburetor is set for a medium speed, if the mix¬ 
ture is weak at low speeds, and rich at high 
speeds, more air should be admitted, but if the 
mixture is rich at low speeds, and weak at 
high, less air should be admitted. Much de¬ 
pends upon the spring. ' 

It is a characteristic of all springs that their 
flexure is in direct proportion to the load im¬ 
posed, up to the elastic limit of the spring. 

The Float Feed Carburetor, always con¬ 
sists of two principal parts: a gasoline recepta¬ 
cle which contains a hollow metal or a cork 
float, suitably arranged to control the supply of 
gasoline from the tank or reservoir, and a tube 
or pipe in which is located a jet or nozzle in 
communication with the gasoline receptacle. 
This tube or pipe is called the mixing chamber. 
The gasoline level is maintained about one-six¬ 
teenth of an inch below the opening in the jet 


The Automobile Handbook 127 

in the mixing chamber. The inductive action 
of the motor-piston creates a partial vacuum in 
the pipe leading from the mixing chamber of 
the carbureter to the motor, thereby causing 
the gasoline to flow from the jet and mixing 
with the air supply, to be drawn into the cylin¬ 
der of the motor in the form of an explosive 
mixture. 

Spraying Carburetors. In this type of car¬ 
buretor the quantity of gasoline delivered is 
not proportional to the volume of air delivery 
at different rates of flow. This difficulty has, 
however, been met by providing a supplemen¬ 
tary air inlet to the carbureter, which may be 
regulated by the driver at will. 

Another method of correcting the variations 
in the proportions consists in providing a 
second spray nozzle. In the majority of cases 
in which multiple nozzle carburetors are used, 
there are two nozzles, practically two carbure¬ 
ters, a small one for idle running, and slow 
speeds, and a larger one for heavy work. In 
some instances, three, and even four nozzles are 
used. 

In case an extra gasoline nozzle is used it is 
generally so placed that the suction has little 
or no effect upon it until a sufficient engine 
speed has been attained to cause the auxiliary 
air valve to open. The additional nozzle is 
placed in the stream of air from this auxiliary 
valve and the incoming air picks up a sufficient 
quantity of fuel to maintain the correct propor- 


128 


The Automobile Handbook 


tions of the mixture. This and other variations 
appear in the following pages. 

Auxiliary Air-Yalve. It has been deter¬ 
mined from the result of experiments that to 
get the maximum power at any speed from a 
gasoline motor equipped with a float-feed car¬ 
buretor, the jet of the carburetor.must have a 
larger opening for low speeds than for high 
speeds. As this practice would require a very 
delicate adjustment it consequently becomes 
almost impracticable, because necessitating a 
constantly varying regulation for each frac¬ 
tional variation of speed of the motor. The 
difficulty may be obviated by the use of an aux¬ 
iliary air-valve, located in the induction-pipe 
close to the inlet-valve of the motor. 

The jet of the carburetor is set for the maxi¬ 
mum quantity of gasoline at the slowest speed 
of the motor, and as the speed is increased the 
auxiliary air-valve comes into action and in¬ 
creases the supply of air passing through the car¬ 
bureter, thereby reducing the suction or partial 
vacuum at this point, and maintaining a con¬ 
stant quality of mixture at all times. 

The auxiliary air valve has been attached to a 
dash pot construction in many makes of modern 
carburetors. The dash pot may operate with 
air or with gasoline for its fluid, but in either 
case the purpose is to prevent sudden opening 
and closing of the valve or “fluttering.” Such 
fluctuation is a cause of noise and also tends 
to destroy the proportions of the mixture. 


The Automobile Handbook 


129 


Frequently it is observed that the intake to 
the carburetor is so restricted that noise issues, 
and a little further investigation in such cases 
will disclose, in all probability, that wire-draw¬ 
ing is one of the ills. It is not alone the noise 
that is objectionable in such cases; the power 
of the motor will be less, due to the restriction 
which has the effect of reducing the weight of 
mixture that enters into the cylinders, and the 
power of a motor is undoubtedly proportional 
to the weight of mixture that enters the cylin¬ 
ders, assuming, of course, that the same is in 
acceptable form, and that it is completely 
burned. True, there must be a depression in 
the carburetor in order that there will be a dif¬ 
ference in pressure, so that gasoline will be 
sucked into the train of air; equally true, it is 
of the greatest importance to have the depres¬ 
sion as low as possible in order that the power 
of the motor will be a maximum. If the depres¬ 
sion is but slight, provided the carburetor is 
I)roperly designed, the amount of fuel entrained 
will be adequate for the purpose. If, on the 
other hand, the depression is very large and 
holds considerable fuel, it will soon be found to 
be wasteful of the liquid. 

With the low grades of fuel now in use, wire¬ 
drawing is very harmful, inasmuch as it tends 
to separate the gasoline from the air and causes 
the gasoline vapor to again become a liquid and 
deposit on the tubing walls. 


130 


The Automobile Handbook 


Effect of Cold on Gasoline. The tempera¬ 
ture has a very marked effect on the rapidity 
with which gasoline vaporizes, and in cold 
weather it is necessary to supply heat to the 
carburetor. 

The carburetor should preferably be jacket¬ 
ed, and it may be warmed either from the circu¬ 
lating water, or by taking a small quantity of 
the hot gases from the exhaust pipe. If water is 
used it should be taken from a point just be¬ 
yond the discharge of the pump, and should be 
delivered to the return pipe from the engine 
jacket to the radiator. 

Whether exhaust gases or water is used, the 
flow should be regulated by a cock, otherwise 
too muchJieat will be received in warm weather. 
When the carburetor is cold, the engine may be 
started by pouring warm water over it, care be¬ 
ing taken not to let any portion of the water 
get into the gasoline through any aperture in 
the top. Another method of warming up the 
carbureter is to wring cloths out of hot water, 
and wrap them around it. 

While it is not generally realized, the flow of 
gasoline through the nozzle is greatly influenced 
by the temperature of the liquid. Gasoline at 
very low temperatures, such as freezing, and 
slightly above, is reduced as much as 30% in 
volume of flow below the point reached when the 
liquid itself is warmed to between 65° and 80° 
Fahrenheit. This forms one more reason for 
jacket heating on all carburetors. 


The Automobile Handbook 


131 


Carburetor Inspection. The float valve of 
the carburetor should be tested for leaks by 
opening the valve-between it and the tank and 
looking for gasoline drip. If gasoline escapes, 
it may simply be because the float isn set too 
high, so that it does not close the needle valve 
before gasoline issues from the spray nozzle. 
Or, it may be that the valve itself leaks. 

At this stage, it is well to assume that the 
float is properly adjusted, and to begin by shut¬ 
ting off the main gasoline valve, and then un¬ 
screwing the washout plug below the needle 
valve. It may be found that dirt, waste, or a 
splinter of wood has got past the strainer, 
through which, presumably, the gasoline passes 
on its way to the float, and is lodged in the 
needle-valve opening. It may be of advantage 
to open the top of the float chamber, which can 
usually be done without disturbing other parts, 
and take out the float and needle valve. A lit¬ 
tle gasoline washed down through the needle- 
valve orifice will then generally carry away any 
dirt that may have clung to the valve when the 
plug was unscrewed. If the gasoline still drips 
when the parts are reassembled, the mixing 
chamber should be opened and the top of the 
spray nozzle examined to see if gasoline is es¬ 
caping from it. An electric light should be 
used in making an examination of the carbu¬ 
reter, as, with any other illuminant, a fire might 
be started. The portable electric flashlights 
answer the purpose very well. 


132 * The Automobile Handbook 


Occasionally a carburetor is found to be too 
large for the engine, or to have too large a 
spray orifice. The advice has been given in 
such a case to reduce the size of the spray ori¬ 
fice by lightly pening the top of it with a ham¬ 
mer. This is counsel of doubtful value, even 
if the hole be afterward reamed true, since it is 
manifest that the burr formed in the top of the 
orifice cannot possibly be deep enough to be at 
all regular in its form. It will almost inevita¬ 
bly throw a jet slantwise, instead of straight, 
and this je+ failing to strike the main part of 
the air stream will be only partly atomized, 
with resulting misfiring and general bad be¬ 
havior, especially at low speeds. If a new noz¬ 
zle of smaller size cannot be substituted, the 
best thing to do in case there is no needle valve 
to adjust the flow of gasoline to the jet is prob¬ 
ably, to warm the ingoing air as much as possi¬ 
ble, in order to make evaporation by tempera¬ 
ture take the place of atomizing due to the air’s 
velocity. 

Holly Carburetor, Model H. This carbure¬ 
tor is shown in Fig. 65. Before the fuel enters 
the float chamber it passes a strainer disk A 
which removes all foreign matter that might in¬ 
terfere with the seating of the float valve B 
under the action of the cork float and its lever 
C. Fuel passes from the float chamber, D, into 
the nozzle well E, through a passage F, drilled 
through the wall separating them. From the 


The Autotnobile Handbook 


133 


nozzle well the fuel enters the nozzle proper, G, 
through the hole H, and then rises past the 
needle valve I, to a level in its cup-shaped upper 
end, which just submerges the lower end of a 
small tube, J, which has its outlet at the edge of 
the throttle disk. 



Fig. 65 

Holly Carburetor, Model “H” 


Cranking the engine, with the throttle kept 
nearly closed, causes a very energetic flow of air 
through the tube J and its calibrated throttling 
plug K, but the lower end of this tube is sub¬ 
merged in fuel, with the engine at rest. There- 





























134 


The Automobile Handbook 


fore, the act of cranking automatically primes 
the motor. With the motor turning over, under 
its own power, flow through the tube J takes 
place at very high velocity, thus causing the fuel 
entering the tube with the air to be thoroughly 
atomized upon its exit from the small opening 
at the throttle edge. This tube is called the 
‘‘low speed tube” because, for starting and idle 
running, all of the fuel and most of the air in 
the fuel mixture are taken through it. 

As the throttle opening is increased beyond 
that needed by idling of the motor, a consider¬ 
able volume of air is caused to move through the 
passage bounded by the conical walls L of the 
so-called strangling tube. In its passage into 
the strangling tubej the air is made to assume an 
annular, converging-stream form, so that the 
point in its flow at which it attains its highest 
velocity is in the immediate neighborhood of the 
upper end of the “standpipe” M, set on to the 
body of the nozzle piece G. The velocity of a_ir 
flow being highest at the upper, or outlet, end of 
the standpipe, the pressure in the air stream 
is lowest at the same point. For this reason 
there is a pressure difference between the top 
and bottom openings of the pipe M, thus causing 
air to flow through it from bottom to top, the air 
passing downward through the series of open¬ 
ings N in the standpipe supporting-bridge arid 
then up through the standpipe. 

With a very small throttle opening, the action 
through the standpipe keeps the nozzle thor- 


The Automobile Handbook 


135 


oughly cleaned out, the fuel passing directly 
from the needle opening into the entrance of the 
standpipe. To secure the utmost atomization 
of the fuel, the passage through the standpipe is 
given aspirator form, which further increases 
the velocity of the flow through it, and insures 
the greatest possible mixture of the fuel with the 
air. A further point is that the atomized dis¬ 
charge of the standpipe enters the air stream at 
a point at which the latter attains its highest 
velocity and lowest pressure. 



There is but one adjustment, the needle valve 
I. The effect of a change in its setting is mani¬ 
fest equally over the whole range of the motor. 

Holly Carburetor, Model G. This design is 
especially for Ford cars. Its method of opera- 



























136 The Automobile Handbook 

tion is identical with that of the Model H, its 
chief differences as compared with the other 
model being structural ones, giving a horizontal 
instead of a vertical outlet, a needle valve con¬ 
trolled from above, and a general condensation 
of the design to secure compactness. 

Fuel enters the carburetor, shown in Fig. 66, 
by way of a float mechanism in which a hinged 
ring float, in rising with the fuel, raises the float 
valve into contact with its seat. The seat is a 
removable piece and the float valve is provided 
with a tip of hard material. 

From the float chamber the gasoline passes 
through the ports E to the nozzle orifice in 
which is located the pointed end of the needle 
F. It is noted that the ports E are well above 
the bottom of the float chamber, so that, even 
should water or other foreign matter enter the 
float chamber it would have to be present in a 
considerable quantity before it could interfere 
with the carburetor operation. 

A drain valve D is provided for the purpose 
of drawing off whatever sediment, or water, may 
accumulate in the float chamber. The float level 
is so set that the gasoline rises past the needle 
valve F and fills the cup G to submerge the 
lower end of the small tube H. Drilled passages 
in the casting communicate with the upper end 
of this tube with an outlet at the edge of the 
throttle disk. The tube and passage give the 
starting and idling actions, as described in con¬ 
nection with the Model H. 


The Automobile Handbook 


137 


The strangling tube I gives the entering air 
stream an annular converging form, in which 
the lowest pressure and highest velocity occur 
immediately above the cup G; thus it is seen that 
the fuel issuing past the needle valve F is imme¬ 
diately picked up by the main air stream at the 
point of the latter’s highest velocity. 

The lever L operates the throttle in the mix¬ 
ture outlet, and a larger disk with its lever S is 
a spring-returned strangler valve in the air in¬ 
take, for facilitating starting in extremely cold 
weather. 


138 


The Automobile Handbook 


Kingston Carburetor. The Kingston carbu¬ 
retor, Fig. 67, uses a ball type of auxiliary 



pKingston Carburetoi 


air valve instead of the employment of spring 
control dashpot, diaphragm or auxiliary air 
valve. The main air intake A communicates 


with the vertical mixing chamber B, in which 


the sides C are beveled outward, giving a center 
tube effect, so that the air current converges 
above the nozzle N, as indicated by the arrows. 
D marks the exit to the motor controlled by the 
butterfly throttle E. Auxiliary air enters 
through five circular openings G, arranged in 
a semi-circle in the floor of an extension H of 
the mixing chamber. Each of these five open¬ 
ings- consists of a bushing K threaded into the 
opening in the extension H, and having its top 
beveled to receive a five-eighths inch bell metal 
bronze ball L, which is retained in position by 
a threaded bushing M, fitting in the top of the 
extension IT. It has a pair of downward project- 






















The Automobile Handbook 


139 


ing hooks N for preventing the ball getting out 
of position, but not interfering with the ball 
rising vertically when forced to do so by the 
pull of the motor, at which time additional air 
is admitted. Two others of the five auxiliary 
entrances are shown at I and 0, all of the five 
containing balls of the same size and weight. 
The air entering through the openings guarded 
by these balls has an unrestricted passage into 
the mixing chajnber and thence to the motor. 
Any ball is easily moved by unthreading the 
cap M, after which the ball can be lifted out. 

The gasoline enters the carburetor from 
the gasoline tank by way of the connec¬ 
tion J, which is guarded by the needle valve R, 
operated through the lever S, pivoted in the 
side of the casting and with its long arm bear¬ 
ing on the top of the cork float. The float is 
fitted with a metal bushing. Complete control 
of the nozzle N is through the needle valve V, 
which, at the top of the carbureter, has a T- 
piece X, by which it can be raised or lowered, 
thereby regulating the flow of gasoline. A 
feature of the throttle connection T is the ser¬ 
rated lower face of its hub W, so that by loos¬ 
ening a lock nut Z, the handle T may be turned 
in any direction most convenient. The air in¬ 
take A consists of an L-shaped piece secured 
to the carbureter casting by a nut P, and in the 
base of this is a circle of openings F where cur¬ 
rents of air can enter, the object of these open¬ 
ings being that by priming the carburetor, and 


140 The Automobile Handbook 

overflowing the open mouth of nozzle N the 
gasoline falls to the vicinity of the holes F, and 
the air entering through these openings will 
facilitate the breaking up of the gasoline, and 
thereby assist the starting of the motor. 



Fig. 68 

Double Bowl Carburetor 


Rayfield Carburetor. The Rayfield carbure¬ 
tor has no direct adjustment for the nozzle 
opening such as would be provided by a screw 
needle valve, but to take the place of such an 
adjustment a type of lever mechanism is used" 
that increases or decreases the gasoline supply 





















The Automobile Handbook 141 

according to the degree of throttle opening, and 
also provides means for adjusting the fuel flow 
for high or low speeds independently of each 
other. Adjustment is provided through two 
screws with milled heads, one of these serving to 
fix the position of the nozzle adjustment at low 
engine speeds or with a nearly closed throttle 
and the other one operating only when the throt¬ 
tle is more- than half way open. The construc¬ 
tion of this instrument is clearly shown in Figs. 
69, 70 and 71, and the method of adjustment is 
described on the following pages. 

Model D, Fig. 69—Adjusting low speeds:— 
Close needle valve by turning low speed screw 
to the left until arm U slightly leaves contact 
with the cam. Then turn to the right one and 
one-half turns, open throttle one-quarter, prime 
carburetor and start motor. Close throttle until 
motor runs slowly without stopping. Turn low 
speed screw to the left one notch at a time until 
motor idle§ smoothly. If motor does not throttle 
low enough turn screw in stop arm to the left 
with a screw driver. Carburetor is now adjusted 
for low speed. 

Adjusting high speed:—Now open the throt¬ 
tle slowly until wide open. Should motor back¬ 
fire turn high speed adjusting screw to the right, 
a half turn at a time, until motor runs without 
a miss. Should motor not backfire turn high 
speed adjusting screw to the left until it does, 
then to the right until motor runs smoothly and 
powerfully. 


142 


The Automobile Handbook 


Do not use low speed adjustment to get a cor¬ 
rect mixture at high or intermediate speeds. 

Should motor backfire or mixture be too light 
at intermediate speeds (throttle about % open) 



Rayfield Carburetor, Model “D”. A, Float Cham¬ 
ber. B, Mixing Chamber. C, Flange. D, Throt¬ 
tle Lever. E, Gasoline Intake. H, Gas Arm. J, 
Dash Adjustment. K, Air Valve. L, Needle 
Valve. M, Regulating Cam. P, Air Adjustment. 
R, Air Lock. S, Drain Plug. T, Priming Cap. 
U, Needle Arm. F, Water Connection. G, 
Priming Lever. N, Low Speed Adjustment. O, 
High Speed Adjustment. V, Primary Air In¬ 
take. W, Cam Shaft. 

turn air valve adjustment P to the right a turn 
or two, thus increasing the spring tension and 
decreasing quantity of air slightly. 

Remember that it is best to use all the air that 
the motor will handle without being sluggish. 

Do not change the float level. It is correctly 
set at the factory. Always prime carburetor 


























The Automobile Handbook 143 

well before starting motor. Pull steadily oi» 
primer string. Don’t jerk. 

Do not cut down the air supply, unless the 
gasoline adjustments fail to give you a powerful 
and fast mixture. 

If motor does not get the correct mixture at 
intermediate speed or high speed, do not try to 
remedy it through a low speed adjustment. Re¬ 
member, the low speed adjustment is to be ad¬ 
justed only when the motor is running idle. 

In starting motor, do not open throttle more 
than one-quarter. The motor will start more 
readily with the throttle slightly opened and it is 
harmful as well as useless to race the motor in 
starting. 

Before cranking motor pull dash button up. 
After motor has “warmed up” push dash button 
down to Running Position. 

In stopping motor pull up dash button, open 
throttle about % inch, and switch off ignition, 
thus leaving a sufficient volume of rich mixture 
in the cylinders, which assures easy starting 
when the motor is again used. 

Models G and L, Figs. 70 and 71, have no air 
valve adjustment and only two gasoline adjust¬ 
ments. 

Always adjust carburetor with dash control 
down. Low speed adjustment must be completed 
before adjusting “high.” 

Adjusting low speed:—"With-throttle closed, 
and dash control down, close nozzle needle by 
turning Low Speed adjustment to the left until 




HIGH-SPEED 
ADJUST^jEN T 

TU3N TO ft^GHT'fbR. 

’ . -V KO*E OA5 . 


;<5A50LINE 

INTAKE 

■CONNECTION 


LOW SPEED\J 
ADJUSTMENT 

Turn TO RIGHT fORMOKfOMt 


Fig. 71—Rayfield Carburetor, Model “G”, Internal 
Construction 


144 The Automobile Handbook 


Fig. 70 

Rayfield Carburetor, Model “G”. D, Throttle Arm. 
G, Priming Lever. H, Gasoline Arm. M, Regu¬ 
lating Cam. S, Drain Cock. U, Needle Valvo 
Arm. X, Drain Cock. J, Gasoline Control Lock. 






















The Automobile Handbook 145 

Block U slightly leaves contact with the cam M. 
Then turn to the right about three complete 
turns. Open throttle not more than one-quarter. 
Prime carburetor by pulling steadily a few sec¬ 
onds on priming lever G. Start motor and allow 
it to run until warmed up. Then, with retarded 
spark, close throttle until motor runs slowly 
without stopping. Now, with motor thoroughly 
warm, make final low speed adjustment by turn¬ 
ing low speed screw to left until motor slows 
down, and then turn to the right a notch at a 
time until motor idles smoothly. 

If motor does not throttle low enough, turn 
stop arm screw A to the left until it runs at the 
lowest number of revolutions desired. 

Adjusting High Speed:—Advance spark 
about one-quarter. Open throttle rather quickly. 
Should motor backfire it indicates a lean mix¬ 
ture. Correct thi3 by turning the high speed 
adjusting screw to the right about one notch at 
a time, until the throttle can be opened quickly 
without a backfiring. 

If “loading” (choking) is experienced when 
running under heavy load with throttle wide 
open, it indicates too rich a mixture. This can 
be overcome by turning high speed adjustment 
to the left. 

Adjustment made for high speed will in no 
way affect low speed. Low speed adjustment 
must not be used to get a correct mixture at high 
speed. Both adjustments are positively locked. 

Starting -.—Before starting motor when cold 


146 


The Automobile Handbook 


observe the following. Open throttle not more 
than one-quarter. Enrich the mixture by pull¬ 
ing up dash control. Prime carburetor by pull¬ 
ing on priming lever G for a few seconds. 

When stopping motor, pull up dash control. 
Open throttle about one-quarter and switch off 
ignition. This leaves a rich mixture in the 
motor, which insures easy starting. 

Raising dash control enriches the mixture by 
lifting the nozzle needle. Control button should 
be down for running, except when a richer mix¬ 
ture is required. 

Pull button up full distance for starting. 

Adjustment of carburetor should always be 
made with dash control down and motor warm. 


The Automobile Handbook 


147 


Schebler Carburetors. This make of instru¬ 
ment has been built in a number of different 
models, the first one of which to be used in large 
numbers was the Model D. All of the important 
types of Schebler carburetors now in use are 
described and instructions given for their ad¬ 
justments on the following pages. 



Fig. 72 

Schebler Carburetor, Model “L”. A, Auxiliary Air 
Valve. B, Gasoline Needle Valve. C, Priming 
Lever. D, Intermediate Speed Cam. E, High 
Speed Cam. 

The Model L carburetor, Fig. 72, is a type of 
lift needle carburetor and is so designed that the 
amount of fuel entering the motor is automatic¬ 
ally controlled by means of a raised needle work¬ 
ing automatically with the throttle. The adjust¬ 
ment or control of gasoline in this instrument 






















148 


The Automobile Handbook 


can be adjusted for low, intermediate or high 
speed, each adjustment being independent and 
not affecting either of the other adjustments. 

In adjusting the carburetor, first make adjust¬ 
ment on the auxiliary air valve A so that it seats 
firmly but lightly; then close the needle valve by 
turning the adjustment screw B to the right 
until it stops. Do not use any pressure on this 
adjustment screw after it meets with resistance. 
Then turn it to the left from four to five com¬ 
plete turns and prime or flush the carburetor by 
pulling up the priming lever C and holding it 
up for about five seconds. Next, open the throt¬ 
tle about one-third, and start the motor; then 
close the throttle slightly, retard the spark and 
adjust throttle lever screw F and needle valve 
adjusting screw B so that the motor runs at the 
desired speed and fires on all cylinders. 

After getting a good adjustment with the 
motor running idle, do not touch the needle valve 
adjustment again, but make all intermediate and 
high speed adjustments on the dials D and E. 
Adjust pointer on the first dial D from the 
number 1 towards 3, about half way between. 
Advance the spark and open throttle so that the 
roller on the track running below the dials is 
in line with the first dial. If the motor backfires 
with the throttle in this position, and the spark 
advanced, turn the indicator a little more toward 
number 3; or if the mixture is too rich turn the 
indicator back or toward number 1, until motor 
is running properly with the throttle in this posi- 


The Automobile Handbook 149 

tion, or at intermediate speed. Now, open the 
throttle wide and make adjustment on the dial 
E for high speed in the same manner as for in¬ 
termediate speed on dial D. 

In the majority of cases in adjusting this car¬ 
buretor the tendency is to give too rich a mix¬ 
ture. In adjusting the carburetor both at low, 
intermediate and high speeds, cut down the gaso¬ 
line until the motor begins to backfire, and then 
increase the supply of fuel, a little at a time, 
until the motor hits evenly on all the cylinders. 
Do not increase the supply of gasoline by turn¬ 
ing the needle valve adjusting screw more than 
a notch at a time in the low-speed adjustment, 
and do not turn it any after the motor hits regu¬ 
larly on all cylinders. In making the adjust¬ 
ments on the intermediate and high speed dials, 
do not turn the pointers more than one-half way 
at a time between the graduated divisions or 
marks shown on the dials. 

The Model R Schebler carburetor, Fig. 73, is 
a single jet raised needle type of carburetor, 
automatic in action. The air valve controls the 
lift of the needle and automatically proportions 
the amount of gasoline and air at all speeds. 

The Model R carburetor is designed with an 
adjustment for low speed; as the speed of the 
motor increases the air valve opens, raising the 
gasoline needle, thus automatically increasing the 
amount of fuel. The carburetor has but two ad¬ 
justments—the low speed needle adjustment, 
which is made by turning the air valve cap and 


150 


The Automobile Handbook 


an adjustment on the air valve spring for chang¬ 
ing its tension. 

, This carburetor has an eccentric which acts on 
the needle valve, intended to be operated either 
from the steering column or from the dash, and 
insures easy starting, as by raising the needle 
from the seat an extremely rich mixture is fur¬ 
nished for starting, and for heating up the motor 
in cold weather. A choker in the air bend is also 
furnished. 


n 



Schebler Carburetor, Model “R”. A, Low Speed 
Adjustment. B, Starting Cam Lever. C, Needle 
Valve Connection. D, Starting Cam. E, Needle 
Valve. P, High Speed Adjustment. 

When carburetor is installed see that lever 
B is attached to steering column control or dash 
control, so that when boss D of lever B is against 
stop C the lever on steering column control or 
dash control will register “Lean” or “Air.” 












The Automobile Handbook 151 

This, is the proper running position for lever B. 

To adjust carburetor turn air valve cap A 
clockwise or to the right until it stops, then turn 
to the left or anti-clockwise one complete turn. 

To start engine open throttle about one-eiglith 
or one-quarter way. When motor is started let 
it run till engine is warmed, then turn air valve 
cap A to left or anti-clockwise until engine hits 
perfectly. Advance spark three-quarters of the 
way on quadrant, if engine backfires on quick 
acceleration turn adjusting screw F up (which 
increases tension on air valve spring) until ac¬ 
celeration is satisfactory. 

Turning air valve cup A to right or clockwise 
lifts needle E out of nozzle and enriches mix¬ 
ture ; turning to left or anti-clockwise lowers the 
needle into nozzle and makes mixture lean. 

When motor is eold or car has been standing, 
move steering column or dash control lever to¬ 
wards “Gas” or “Rich” which lifts needle E 
out of gasoline nozzle and makes rich mixture 
for starting. As motor warms up, move control 
lever gradually back towards “Air” or “Lean” 
to obtain best running conditions until motor has 
reached normal temperature. When this tem¬ 
perature is reached control lever should be at 
“Air” or “Lean.” 

For best economy and power, the slow speed 
adjustment should be made as lean as possible. 


152 The Automobile Handbook 

Stromberg Carburetors are made with a noz¬ 
zle, the opening in which is not adjustable. This 
nozzle is a separate part of the carburetor and 
is screwed into place from below. In order to 
adjust the gasoline flow it is necessary to remove 
one nozzle and replace it with one having a larg¬ 
er or smaller opening. The nozzles are marked 
according to drill gauge sizes and the opening 
becomes larger as the number becomes lower, that 
is to say, a number 59 is larger than a number 
60 and a number 58 is larger than a number 59. 

If, after making low speed adjustment it is 
found that the air valve remains off its seat or 
that indications of a rich mixture are still pres¬ 
ent, the nozzle is too large. If the high speed 
adjustment has to be screwed very tight it indi¬ 
cates that the nozzle is too small. In changing 
nozzles do so one size at a time, that is, do not 
drop from number 60 to a number 58, but use 
a 59 first. 

Instructions for type A. Type A, Fig. 74, is 
a water jacketed carburetor. It has its spray 
nozzle PN mounted in the center of the carbure¬ 
tor with its point 3-16 of an inch above the 
normal gasoline level and surrounded by a 
modified venturi tube. This nozzle is propor¬ 
tionate in size to the carburetor and never needs 
attention or adjustment. 

After the carburetor is installed and the gaso¬ 
line turned on, note the level of the gasoline in 
the float chamber. It should be about one inch 


The Automobile Handbook 


153 


from the lower edge of the glass. This level is 
adjusted at the factory and should be right. In 
case it is obviously wrong, remove the dust cap 
D and turn the adjusting screw S until the 
proper level is obtained. If the gasoline is too 
high, screw the nut down. If gasoline is too 
low, screw the nut up. Don’t change unless 
absolutely necessary. 



Stromberg Carburetor, Model “A” 


To start the motor close the valve S3 in the 
hot air horn H. The motor should then start 
on the second or third turn of the crank. If 
not, open the valve and it ought to start on 
the next turn. Great care should be taken to 
see that this valve is instantly opened as the 
motor starts, and- is kept open. 

Season adjustments. Open and close shutter 
SA—open in summer and closed in winter. 

Low speed adjustment. Turn up the adjust- 









154 


The Automobile Handbook 


ing nut A until the spring SI, which is the low 
speed spring, seats the valve lightly. See that 
the high speed spring above B is free and does 
not come in contact with the nut on top of the 
auxiliary air valve stem. Start the motor and 
turn nut A up or down until motor idles prop¬ 
erly. This is the low speed adjustment. 

High speed adjustment. Advance the spark 
and open the throttle. If the motor backfires 
through the carburetor, turn high speed adjust¬ 
ing nut B up until backfiring ceases. If, with 
this adjustment and running at low speeds, 
motor gallops, or the carburetor loads up, the 
mixture is too rich. The nut B should then be 
turned down until galloping or loading ceases. 
This is the high speed adjustment. The spring 
above nut B should always have at least 1-32 
inch clearance between it and the nut at the top 

when the motor is at rest. 

% 

Instructions for type B. Type B, Fig. 75, 
is a concentric type carburetor. It has its spray 
nozzle PN mounted in the center of the car¬ 
buretor, and in the center of the float chamber, 
with its point 3-16 of an inch above the normal 
gasoline level and surrounded by a modified 
venturi tube. 

The level of the gasoline in the float chamber 
should he about 15-16 oi: an inch from the lower 
edge of the glass marked X. This level is adjust¬ 
ed at the factory and should be right. In case 
it is wrong, remove the dust cap D and turn 
the adjusting screw S until the proper level is 


The Automobile Handbook 155 

obtained. If the gasoline is too high screw the 
nut down. If the gasoline is too low screw the 
nut up. Don’t change unless absolutely neces¬ 
sary. 


Fig. 75 

Stromberg Carburetor, Model “B” 

Low speed adjustment. Turn up the adjust¬ 
ing nut A until the spring SI, which is the low 
speed spring, seats the valve lightly. See that 
the high speed spring above B is free and does 
not come into contact with the nut on top of 
the auxiliary air valve stem. Start the motor 
and turn nut A up or down until motor idles 
properly. This is the low speed adjustment. 

High speed adjustment. Advance the spark 
and open the throttle. If motor backfires 
through the carburetor, turn high speed adjust¬ 
ing nut B up until backfiring ceases. If, with 
this adjustment and running at low speeds 
motor gallops, or the carburetor loads up, the 













156 The Automobile Handbook 

mixture is too rich. The nut B should then be 
turned down until galloping or loading up 
ceases. This is high speed adjustment. The 
spring above^iut B should always have at least 
1-32 inch clearance between it and the nut at 
the top when the motor is at rest. 


L 



Stromberg Carburetor, Model “C” 


Instructions for type C. Type C, Fig. 76, 
is equipped with two separate gasoline spray 
nozzles. The first or primary nozzle PN is 
mounted in the venturi tube V; this nozzle 
supplying sufficient gasoline for all speeds up to 
twenty or twenty-five miles per hour. The sec¬ 
ond or auxiliary nozzle is mounted just beneath 
the secondary gasoline needle valve ANV in 
the auxiliary air passage A A, and is opened by 
the lever L operating over a fulcrum F by the 
opening of the auxiliary air valve AY. 









The Automobile Handbook 157 

Turn up the lower adjusting nut N, located 
underneath the auxiliary air valve, so that the 
valve is brought up to seat, then give two full 
turns to the right as a starting adjustment. 
This valve should be seated on extreme idle. 
The spring SI is the low speed spring and does 
the work up to the opening of the auxiliary 
needle. 

Start the motor and turn low speed nut N up 
or down until the motor idles properly, then 
advance the spark, open the throttle, and if the 
motor backfires turn nut LN down until it 
ceases. If mixture is too rich, turn it up. Be 
sure that nut LN and lever L have some clear¬ 
ance on low speed. 

The proper gasoline level is about 1 inch 
from the lower edge of the glass. If more than 
% inch either way remove the dust cap and 
adjust by screws. 

High speed adjustment. The high speed is 
regulated by the lock nut LN on top of the 
auxiliary air valve. As it is raised or lowered 
it determines the point at which the auxiliary 
needle valve ANY will be brought into play. 
To lock nut LN should be about 3-32 of an inch 
above the lever L for normal adjustment, but 
this distance can be increased or decreased to 
suit the motor. 

To find primary nozzle size. If the mixture 
is too rich on low speed after adjustments are 
made according to instructions, take out the 
plug P and remove the nozzle PN with a screw- 


158 


The Automobile Handbook 


driver. Insert smaller nozzle (59 is smaller 
than 58). If the mixture is too lean on low 
speed a larger nozzle should be inserted. If 
the engine misses on low speed it may be caused 
by an air leak, and all the joints between the 
carburetor and the motor should be examined 
before a large nozzle is inserted. 



Fig. 77 

Stromberg Carburetor, Model “G” 


Instructions for type G. Type G, Fig. 77, 
is a non-water-jacketed model furnished in 
either single or double jet according to motor 
requirements. 

Air adjustments. There are only two adjust¬ 
ments that ever need attention, A, the low speed 
nut, and B, the high speed nut. 

With the motor at rest, set the high speed nut 
B so there is at least 1-16 of an inch clearance 
between the spring G and the nut X above it 
This is imperative. 







The Automobile Handbook 159 

Set the low speed nut A so the air valve E is 
seated lightly. Do' not adjust carburetor until 
motor is thoroughly warmed up. When motor 
is warm and with spark retarded adjust nut 
A up or down until motor runs smoothly at low 
speed. To determine proper adjustment open 
the air valve with finger by depressing X 
slightly. If, when so doing, motor speeds up 
noticeably it indicates too rich a mixture and 
A should he turned down notch by notch. If, 
on the other hand, motor dies suddenly when 
slightly opening the air valve it indicates too 
lean a mixture and A should be turned up until 
this is overcome. 

Once properly set for idling do not change 
this adjustment when making the high speed 
adjustment. 

Advance the spark at the normal position and 
open the throttle gradually. If motor back¬ 
fires through the carburetor it is positive in¬ 
dication of too lean a mixture and nut B should 
be turned up notch by notch until this is over¬ 
come. 

If mixture is too rich, as indicated by loading 
of the motor and heavy black smoke from the 
exhaust, turn B down until motor operates 
properly. A further test for the correct mix¬ 
ture at high speed can be made by depressing 
the air valve when the motor is running at this 
speed. If when so doing motor speeds up it 
indicates too rich a mixture. 

Turning either adjusting nut up means a 


160 The Automobile Handbook 

richer mixture or more gas. Down means a 
leaner mixture or more air. To get highest effi¬ 
ciency from this carburetor, hot air equipment 
should be used. 

Double jet type. If, after following the in¬ 
structions given below, and with the motor run¬ 
ning idle at low speed, the air valve E remains 
tightly seated, it indicates too small a primary 
nozzle C, and a larger one should be substi¬ 
tuted. If with the proper adjustment, and after 
stopping the engine, the air valve hangs off its 
seat the primary nozzle is too large and a 
smaller one should be used. To change the pri¬ 
mary nozzle remove the petcock, insert a narrow 
screwdriver and unscrew the nozzle. 

If the mixture at low speed is correct, but in 
order to get the proper high speed adjustment 
it is necessary to turn the nut B up so far that 
the spring G is in contact with X above it, after 
the engine has been stopped, it indicates that 
the auxiliary nozzle J is too small and a larger 
one should be used. If it is necessary, in order 
to get the proper high speed adjustment, to turn 
the nut B down so that there is more than % 
inch clearance between G and X when the en¬ 
gine is idle, it indicates too large an auxiliary 
nozzle and a smaller one should be used. 

Instructions for types H and HA. There are 
only two adjustments on this carburetor, Fig. 
78. A, the low speed, and B for high speed. 
A is a needle valve, seating in an open nozzle, 
the opening of which is usually two sizes larger 


The Automobile Handbook 161 

than is ordinarily necessary, and which per* 
mits an increase in gasoline flow to that extent 
or allows a complete closing. The high speed 
adjustment controls the flow of gasoline for 
high speeds by regulating the time at which the 
secondary needle valve begins to open. 



Fig. 78 

Stromberg Carburetor, Models “H” and “HA” 
To adjust, set the high speed nut B so that 
there is at least 1-32 of an inch clearance be¬ 
tween it and the needle valve cap above it at 
X when the air valve E is on its seat. The 
needle valve does not begin to open until B 
comes into contact with X. Before starting the 
engine be sure that the rocker arm of the dash 
adjustment on the carburetor is not in contact 
with the collar above it at Z when the steering 
post button is all the way down. 

To start the engine, pull the steering post 
control to its highest position, thus producing a 







162 


The Automobile Handbook 


rich mixture. In cold weather it may also be 
necessary to close the air supply in the hot air 
horn by means of a rod connected to R. This 
should be again opened as soon as the engine 
starts. As the engine warms up, gradually 
lower the steering post control and make sure 
that it is at its lowest position before commenc¬ 
ing to adjust the carburetor. 



Fig. 79 

Stromberg Carburetor, Model “K” 


The mixture at low speed is controlled bj r the 
needle valve A. If too rich is indicated, by the 
engine “rolling’’ or il loading/’ turn A up or 
anti-clockwise*. If the mixture is not rich 
enough, turn A down or clockwise. To adjust 
high speed, advance the spark and open the 
throttle. If the mixture is not rich enough 
at high speeds, turn B up or anti-clockwise, 
and if the mixture is too rich turn B down or 
clockwise. 

Instructions for types K and KO. The nut 




The Automobile Handbook 165 

A is the only adjustment on this carburetor, 
Fig. 79. The stem of this nut supports the 
tower end of a spring that controls the air 
valve. This air valve opens downward into the 
air chamber. Turning the nut A clockwise or 
down tightens this spring, admitting less air 
and producing a richer mixture. Turning A 
in the opposite direction or anti-clockwise pro¬ 
duces a leaner mixture. 

Before starting the engine turn A anti-clock- 
wdse until a point is reached where, when lift¬ 
ing or pulling up on A, a decided click is 
heard. This is the air valve coming in contact 
with its seat. Then turn A clockwise or down 
until the click is no longer obtained. This turn¬ 
ing should be a notch at a time, and when the 
click can not be heard, turn two more notches 
in the same direction. To start the engine, 
raise the steering post control to its highest 
position. Gradually lower the control as the 
engine warms up, and make sure that this con¬ 
trol is at its lowest position before starting to 
adjust the carburetor. With the engine warm, 
turn A up or down, notch by notch, until the 
engine idles properly. It should not be neces¬ 
sary to change the initial setting more than a 
few notches. 

The high speed mixture can only be affected 
by changing the nozzle. If the high speed 
mixture is too thin, so that slightly closing the 
dash throttle valve R causes an increase of en¬ 
gine speed, a* larger nozzle should be used. If 


164 The Automobile Handbook 

the high speed mixture is too rich use a smaller 
nozzle. The nozzle size furnished is based on 
18 inches of hot air tubing. If this tubing is 
more than 24 inches long, one size smaller noz¬ 
zle can probably be* used, while if the tubing* 
is less than 10 inches long one size larger may 
be required. 



Fig. 80 

Stromberg Air Bled Jet 


Stromberg Plain Tube Carburetors. These 
instruments differ from the older models in that 
they are of the plain tube type having all air 
passages fixed in size and without valves, while 
the gasoline is measured by the air flow itself. 
The mixture proportion is maintained constant 



































The Automobile Handbook 


165 


by a peculiar form of jet shown in Figure 80, 
in which a small amount of air is mixed with 
the gasoline before the fuel reaches the main 
jets. 

For the Model L carburetor, shown in Figure 
81, also for the corresponding side outlet type, 
Model LB, there are three adjustments, high 
speed, idling and starting. The high speed is 



controlled by the knurled nut marked “High 
Speed” which locates the position of the needle 
past whose point is taken all the gasoline at all 
speeds. Turning this .nut to the right, clock¬ 
wise, raises the needle and gives a richer mix¬ 
ture; while turning to the left gives a leaner 
mixture.’ 

To make an adjustment put the starting lever 
L in the fifth notch, farthest from the float cham- 

















































166 


The Automobile Handbook 


ber and turn the high speed nut to the left 
until the needle reaches its seat as shown by the 
nut moving when the throttle is opened and 
closed. When the needle is on its seat it can 
be felt to stick slightly when the nut is lifted 
with the fingers. Find the point of adjustment 
where this nut just begins to move with the 
throttle opening, then turn 24 notches to the 
right. Now move the starting lever back to the 
0 notch, toward the float chamber, which will 
give a rich adjustment. After starting and 
warming the engine the mixture may be made 
leaner by turning the high speed nut to the left 
until a point is found where the engine responds 
best to quick opening of the throttle and shows 
the best power. 

The low speed or idling adjustment is con¬ 
trolled by the adjusting screw B. The gasoline 
for idling is taken in above the throttle and is 
regulated by dilution with air. Screwing nut 
B in, or clockwise, gives a richer mixture while 
turning it outward gives more air. The best 
adjustment is usually from one-half to three 
turns outward from the seating position. This 
is only an idling adjustment and does not affect 
the mixture above 8 miles per hour. When the 
engine is idling properly there should be a 
steady hiss in the carburetor. If there is a weak 
cylinder or a leak in the manifold, or if the idle 
adjustment is very much too rich, the hissing 
will be unsteady. 

The starting device, called the “economizer,'’ 


The Automobile Handbook 


167 


operates to make a leaner mixture through low¬ 
ering the high speed needle at throttle positions 
corresponding to speeds from five to forty miles 
per hour. The amount of needle drop and con¬ 
sequent leanness is regulated by the position of 
the pointer. 

After making the high speed adjustment for 
best power with the pointer in the 0 notch, place 



Fig. 82 

Stromberg M Carbureter 


the throttle lever on the steering wheel in a 
position corresponding to about 20 miles per 
hour road speed. Then move the pointer clock¬ 
wise, away from the float chamber, one notch at 
a time, until the engine begins to slow down, 
then come back one notch 

The MB carburetors shown in Figure 82 has 
two adjustments, the high speed at A, and a 
low speed setting similar to that for Modef 1/ 
























168 


The Automobile Handbook 


Zenith Carburetor, Model 0. This carbure¬ 
tor, a cross-section of which is shown in Fig. 
83, consists of a float chamber, a carbureting 
chamber, a system of nozzle and air passages and 
a hot air sleeve. 

Zenith carburetors have fixed air and fuel 
openings and operate without automatic valves 
of any kind. With the proper setting once 
secured it is maintained under all conditions. 

Gasoline from the tank enters the strainer 
body D, passes through the wire gauge Dl, and 
enters the float chamber through the valve seat 
8. As soon as the gasoline reaches a predeter¬ 
mined height in the float chamber the metal 
float F, acting through the levers B and collar 
G2, closes the needle valve G1 on its seat. To 
see if there is any gasoline in the carburetor 
remove dust cap Cl. If the needle valve can be 
depressed with the finger there is no gasoline in 
the carburetor. From the float chamber to the 
motor gasoline flows through three different 
channels in various quantities and proportions 
according to the speed of the motor and degree 
of throttle opening. With the throttle fully 
open, most of the gasoline flows through the 
channel E and main jet G. Some flows through 
compensator I, then through K to the cap jet 
H, which surrounds the main jet. The main 
jet and cap jet work together and their com¬ 
bination furnishes the mixture required for 
various engine speeds. At slow speed when the 
throttle T is nearly closed they give but little 


The Automobile Handbook 


169 



Zenith Carburetor, Model “O”. B, Float Control 
Lever. Cl, Dust Cap. D, Strainer Body. Dl, 
Wire Gauze. E, Gasoline Channel. F, Float. 
G, Main Jet. Gl, Needle Valve. G2, Float 
Control Collar. I, Gas Well Opening. H, Sec¬ 
ondary Nozzle. J, Gasoline Well. K, Gasoline 
Passage. L, Drain Plug. N, Idling Adjust¬ 
ment. S, Float Valve Opening. T, Throttle. 
X, Choke Tube. 









































170 


The Automobile Handbook 


or no gasoline, but, as there is considerable suc¬ 
tion on the edge of the butterfly the tube J, 
terminating in a hole near the edge of the but¬ 
terfly, picks up gasoline, which is measured out 
by a small hole at the top of the priming plug. 
The well over compensator I is open to" the air 
through two holes, one of which is indicated-be- 
low the priming plug in the illustration. These 
air openings are important. * 

The hot air sleeve is provided with an air 
strangler actuated by a lever and having 
a coiled spring to bring it back to the open posi¬ 
tion. The flexible hot air tubing is attached to 
this sleeve and feeds the carburetor with air 
that has been heated by contact with the ex¬ 
haust pipe. 

To start the engine open the throttle a little 
way. There will be a strong suction on the tube 
J which will raise the gasoline and thus prime 
the motor. The only adjustment that may be 
useful is the slow speed adjustment, which is 
obtained by the screw 0. Tightening this screw 
restricts the air entrance to the slow speed noz¬ 
zle, giving a richer mixture. 

It is essential that none of the parts shall be 
tampered with, or the size of the jets altered by 
reaming or hammering. These jets are tested 
for actual flow of gasoline and brought to a 
standard. The nominal size of the hole in hun¬ 
dredths of a millimeter is stamped on the jet: 
the higher the number, the larger hole. 

Variables that can be modified for the initial 


The Automobile Handbook 171 

setting of the carburetor: First, the choke tube 
X. This choke tube is held in place by set 
screws and can be removed after taking apart 
the throttle. 

It is really an air nozzle, of such a stream 
line shape that there will be no eddies in the 
air drawn through it. 

For a 4 cylinder engine whose maximum speed 
is 1,500 R. P. M., to obtain the choke number, 
multiply the bore in inches by five and add one 
to the result. 

For 6 cylinder, take a choke one size larger 
up to 4%" bore and two sizes larger above A\/% 
bore. 

If the engine is so built that it can turn up 
to 1,800 R. P. M., increase these results 8%; up 
to 2,000 R. P. M., increase 16%; up to 2,500 
R. P. M., increase 25%. 

A choke tube too small will cause a loss of 
charge at high speed, the car will not attain its 
proper speed. 

A choke tube too large will lead to irregulari¬ 
ties when slowing down and picking up. 

Second—Main Jet C. The effect of this jet 
is most marked at high speed, 1,400 R. P. M. 

Third— Compensating Jet I. This jet, which 
compounds with the main jet, exerts its maxi¬ 
mum influence at lower speeds, 600 R. P. M., 
and in picking up. 

p ourt h—Secondary Well P. This regulates 
the amount of gasoline used when idling. 


172 


The Automobile Handbook 
































































The Automobile Handbook 173 

Zenith Carburetor Principle. The prin¬ 
ciple upon which the Zenith carburetor operates 
may be understood by reference to Figures 84. 
The elementary type of carburetor shown at the 
top consists of a single jet or spraying nozzle 
placed in the path of the incoming air and fed 
from a float feed device. 

While it might be supposed that, with 
increase of engine speed, the flow of both gaso¬ 
line and air would increase in proportion, this 
is not actually the case. The flow of gasoline 
increases in almost direct proportion with the 
engine speed but because the increase of suction 
or vacuum tends to draw the air out thinner and 
thinner, the actual quantity of air does not 
increase in any such proportion and the mixture 
of gas supplied by such a carburetor would 
become richer as the speed increases. 

Referring to the center drawing in the Figure 
it will be seen that, between the float bowl and 
the jet, has been placed a well J which is open 
to the outside air and through which the gaso¬ 
line passes by way of the opening I, thence pass¬ 
ing as before to the jet H. It will be realized 
that the maximum amount of fuel that can reach 
the jet H will be determined by the size of the 
opening I without regard to the suction exist¬ 
ing around H because the flow through I is not 
directly acted upon by this suction. With such 
a device the air flow will increase with speed of 
the engine; and while it will not be in direct 
proportion, there will be an increase over the 


174 


The Automobile Handbook 


whole range of engine speed. Now, inasmuch 
as the flow of gasoline cannot increase beyond 
a certain amount, while the flow of air will 
increase, the mixture furnished by such an ar¬ 
rangement will become weaker with increase of 
engine speed. 

In the Zenith carburetor these two types of 
jets are combined as shown in the lower drawing. 
The direct suction, or richer mixture type, leads 
through pipe E and nozzle G, while the limited 
flow device consists of the well J, opening I, 
passage K and jet H. As the flow of fuel from 
jet H counteracts the change in the flow from 
jet G, the complete mixture may be made prac¬ 
tically of constant proportions over all ranges 
of speed. 


The Automobile Handbook 175 

Chain Drive. This form of power transmis¬ 
sion, an application of which is shown in Figures 
85 and 86, is largely used on motor trucks of 
large load carrying capacity. The chain drive 
system makes use of a jack shaft placed cross¬ 
wise of the car and containing the differential 
gearing. The change speed gearing is usually 
attached to this cross shaft. At the outer ends 
of the driving members of the jack shaft are 
mounted sprockets and a second sprocket is 



fastened to each of the rear driving wheels. 
Between the two sets of sprockets are placed 
chains of the roller type. The reduction in 
speed between engine and road wheels is 
obtained at two points, the first in the bevel 
gears of the jack shaft and the second due to 
the difference in size and number of teeth on the 
front and read sprockets. The rear axle used 
with chain drive systems is a simple solid mem¬ 
ber on the ends of which are carried the wheels. 
The axle may be of tubular, square, rectangular 
or “I” beam section. 









176 


The Automobile Handbook 


Chain drive is satisfactory and efficient as 
long as the chains are kept clean and well oiled. 
Due to their exposed position this is a difficult 



matter and in many cases they have been 
enclosed in cases of pressed or cast steel. 

The roller chains used are described according 



























































The Automobile Handbook 177 

to three measurements; first the pitch which is 
the distance from the center of one roller to the 
center of one adjoining, second the width which 
is the distance across the opening in the links 
in which the sprocket teeth engage and third 
the outside diameter of the rollers, all of these 
sizes being given in inches. 

The distance between the jack shaft sprockets 
and the wheel sprockets is determined and main¬ 
tained by means of radius rods which are fixed 



swivel joints. These rods are made adjustable 
for length so that chain wear may be compen¬ 
sated for. 

Sprockets. The circular instead of the linear 
pitch is often erroneously used in calculating 
the pitch diameter of a sprocket wheel. Refer¬ 
ence to Figure 87 will illustrate the difference 
between circular and linear pitch, and help to 
demonstrate the case more clearly. The view at 
the left of the drawing shows the circular pitch, 





178 The Automobile Handbook 

and the view at the right the linear pitch of a 
gear or sprocket wheel respectively. If the cir¬ 
cular pitch of the gear be one inch and the gear 
has six teeth as shown, the pitch diameter will 
be 6X0.3183, which gives 1.91 inches as the 
pitch diameter. Let the linear pitch of the 
sprocket be also one inch, and with six teeth as 
before. In a sprocket having 6 teeth, the ra¬ 
dius is equal to the linear pitch, as the figure is 
composed of six equilateral triangles, and the 
pitch diameter of the sprocket wheel is conse¬ 
quently 2 inches. 

The pitch of the sprocket must, of course, be 
the same as that of the chain to be used with 
it. Chain pitches usually measure in even 
inches and common fractions. The type of 
chain, whether roller, block or silent, must also 
be considered. It is not safe to use mismated 
chains and sprockets. 

Sprockets, Dimensions of. Table 8 gives the 
pitch diameters of sprockets for roller chain of 
1 inch, 1inch and iy 2 inch pitch, with 7 to 
28 teeth. The outside diameters may be found 
by adding the diameter of the roller to the pitch 
diameter of the sprocket. 

Sprocket Chain Lubrication. The best lubri¬ 
cant for sprocket chains is a constant puzzle. 
If oil is used it is absorbed by the dust which 
settles on the chain. If tallow or other animal 
grease is employed it is pushed away from the 
bearing surfaces, and the latter get dry. The 
ideal lubricant would seem to be something be- 


The Automobile Handbook 


179 


TABLE 8. 


DIMENSIONS OF SPROCKETS FOR ROLLER CHAIN. 


Number of 
Teeth in 
Sprocket. 

1 Inch 
Pitch. 

1 Vi Inch 
Pitch. 

1U Inch 
Pitch. 

Pitch Dia. 

Pitch Dia. 

Pitch Dia. 

7 

2.31 

. 2.88 

3.46 

8 

2.61 

3.27 

3.92 

9 

2.92 

3.65 

4.38 

10 

3.24 

4.04 

4.85 

11 

3.54 

4.44 

5.33 

12 

3.86 

4.83 

5.79 

13 

4.18 

5.22 

6.27 

14 

4.50 

5.62 

6.75 

15 

4.81 

6.01 

7.22 

16 

5.12 

6.41 

7.69 

18 

5.76 

6.41 

8.64 

20 

6.39 

7.99 

9.59 

22 

7.03 

8.79 

10.55 

24 

7.66 

9.58 

11.49 

26 

8.31 

10.38 

12.44 

28 

8.95 

11.19 

13.42 


tween an oil and a grease, too thick to be drawn 
out by absorption, yet soft enough and clinging 
enough to stay in the rollers. This mission is 
approximately fulfilled by a mineral grease, 
such as non-fluid oil, or Keystone grease, which 
are not affected by moderate changes of tem¬ 
perature, and have the clinging quality which 
animal greases lack. The makers of these 
greases, however, do not recommend heating 
them, and they cannot be introduced into the 
links and rollers of the chains, except by ren¬ 
dering them temporarily more fluid than they 
are desired to be in service. A very good lubri¬ 
cant for this purpose is made by dissolving Key¬ 
stone grease in gear case oil, in amounts suffi¬ 
cient to produce a viscous fluid at the boiling 











180 


The Automobile Handbook 


point, which thickened when cold, and would 
just, barely flow. A fairly liberal quantity of 
graphite was added, about half a cupful to three 
quarts of dope, and the chains after cleaning 
were boiled for half an hour or longer in the 
mixture to enable it to penetrate thoroughly. 

Chains, Tire. Tire chains are almost a neces¬ 
sity under many conditions of driving, but in or¬ 
der to avoid damage to the tires themselves the 
chains should be properly applied and properly 
used. Chains should be applied loosely enough 
so that they can work around from place to 
place. Always use chains on both rear wheels, 
never on only one wheel. Make prompt replace¬ 
ment of worn and sharp links, as they will soon 
cut the casing. Apply the chains so that the 
rounded sides of the links and clasps come 
against the rubber. Do not use chains on dry 
streets, and when they are used take them off 
as soon as the emergency has passed. 


The Automobile Handbook 181 

Change Speed Gearing. 

The means provided for securing different 
ratios of speed between the engine and road 
wheels of the car is oftentimes called the 
transmission. Strictly speaking, the transmis¬ 
sion system includes all the parts between en¬ 
gine and wheels; the clutch, universals and 
rear axle parts, as well as the mechanism that 
allows various forward speeds and the reverse. 
The Change Speed Gear takes various forms; 
planetary, friction, sliding gear and magnetic, 
each being described. 

Change Speed Gears. When a gasoline en¬ 
gine is loaded above a certain limit it slows 
down, and the intervals of time between ex¬ 
plosions in each cylinder become so far apart 
that the engine begins to labor, and will finally 
stop altogether, unless some means is provided 
whereby the revolutions of the engine may be 
increased without increasing the number of 
revolutions of the driven shaft, or car axle. 
This is accomplished by means of the change 
speed gear, of which there are two classes, viz., 
those in which an infinite series of variations 
in speed ratio is possible, and those in which 
only a comparatively small number of step-by- 
step ratios can be utilized. In the first class 
are several styles of belt and friction disc 
drives, while in the second class are the change 
speed gears proper, namely, sliding gears, indi¬ 
vidual clutch gears, and planetary gears. 

Belt and* friction drives constitute the only 


182 


The Automobile Handbook 


practical forms of change speed devices id 
which variation from the highest to the lowest 
speed may be possible. In other change speed 
gears the ratio is changed by passing from one 
to another in a series of definite steps. 



Friction Drive. One of the most simple 
methods of changing the speed ratio between 
the motor and the driven shaft is the friction 
drive, which in its simplest form consists of 
two discs at right angles to each other, see Fig. 















































The Automobile Handbook 183 

88, in which b is the fly wheel, the exterior sur¬ 
face of which is made a true plane, and usually 
covered with a special friction metal. A hori¬ 
zontal shaft located crosswise of the car body 
carries a friction pulley c, in close proximity to 
the surface of the fly wheel b. 

' Friction pulley c while secured from turning 
on shaft, may at the same time be shifted along 
at the will of the operator, and thus be 
brought in contact with any portion of the sur¬ 
face of the flywheel, from its center to its outer 
edge. The shaft also carries on its outer ends, 
the sprocket wheels which drive chains e and 
f, by means of which the power is transmitted 
to the drivers. In this device if the friction pul¬ 
ley c be brought in contact with the exact cen¬ 
ter of fly wheel b, no motion will be imparted 
to c, but if it be moved outward from the 
center of the flywheel it will revolve, the num¬ 
ber of revolutions it makes being governed by 
its distance from the center. The maximum 
speed is attained by friction pulley c when it is 
brought into contact with the surface of the fly 
wheel near the periphery of the latter. All po¬ 
sitions of friction pulley c upon one side of the 
center of fly wheel b impart a forward motion 
to the car, and all those on the other side of the 
center impart a reverse, or backing motion. The 
traversing movement of pulley cr along its shaft 
is usually produced by a hand lever provided 
with a notched quadrant, whereby the pulley is 
held at all times in some one of the many posi- 


184 


The Automobile Handbook 


tions giving graduations of speed. The method 
usually employed for making and breaking con¬ 
tact between the friction pulley, and flywheel 
face, consists in mounting the bearings of the 
cross, or countershaft in swinging brackets. An¬ 
other method is to mount these bearings in ec¬ 
centric housings, a slight rotation of which in 
the bearing brackets will cause the shaft and 
with it the pulley to approach, or recede from 
the face of flywheel b. The movement of the 
shaft toward, or away from the flywheel is pro¬ 
duced by a ratchet retained pedal through a 
reducing linkage, which multiplies the foot 
pressure. 

Double Disk Friction Drive. The limitation 
of the single disc and wheel to small power, and 
light loads, has led to the development of the 
double disc, double wheel type of friction geai 
illustrated in Fig. 89. 

The engine shaft is extended, and carries two 
disc fly wheels A and B, while friction pulleys 
C and D are each carried upon one half of 
the cross shaft which is divided at its center. 
Friction pulleys C and D are made to slide 
along the shafts II and F, and are controlled 
by a common sliding mechanism, so that they 
always bear upon points of discs A and B, hav¬ 
ing the same velocities. Driving contact is ef¬ 
fected by swinging shafts II and F in a hori¬ 
zontal plane, and it is obvious that if one of the 
pulleys, D for instance, is pressed against the 
face of A, it will revolve in one direction, while 


The Automobile Handbook 


185 


if brought to bear on B it will revolve in the 
opposite direction, thus providing for a go- 
ahead, or a back-up motion being imparted to 
either friction wheel at will, dependent upon 
whether it is in contact with the forward, or the 



t *arward disc. It is also evident that if one 
of the wheels, say D, is pressed against A, and 
the other wheel C is also pressed against B. 
their shafts will rotate in opposite directions. 
The ratio of the common angular velocity of the 






































186 


The Automobile Handbook 


wheels and their shafts to that of the .discs is 
in proportion to their distance from the center 
of the discs. Sprockets upon the extremities of 
shaft H and F drive the road wheels by chains, 
and sometimes no differential is employed, 
power being shut off when turning corners, or, 
if not, the inevitable slip is divided between the 
frictional contacts, and the contacts of the tires 
with the road. A differential may be mounted 
in either shaft H or F at will. 

Instead of the two shafts H and F being sep¬ 
arate, they may be joined to form a continuous 
shaft and pivoted in the center. The shaft as 
a whole is capable of being slightly swung in a 
horizontal plane about its center, so as to bring 
friction wheel D in contact with one disc, and 
friction wheel C in contact with the other, thus 
producing either the forward or reverse drive. 
In this case a single sprocket is carried by the 
shaft and drives a live rear axle. 

Friction Drives—Materials For. In fric¬ 
tion drives, one of the surfaces in contact is 
generally a metal, while the other surface is 
composed of some kind of organic material, of 
a slightly yielding or conforming nature. Cast 
iron with cork inserts may be used for the me¬ 
tallic surface, the cork inserts serving to in¬ 
crease the co-efficient of friction, besides absorb¬ 
ing any oil that may accidently reach the sur¬ 
faces. Aluminum is no doubt the best material 
for the metallic surface, on account of its plastic 
nature. Copper also possesses similar proper¬ 
ties. For the non-metallic surface, leather is 
good so long as oil is kept from accumulating 


The Automobile Handbook 


187 


on it, but its co-efficient drops rapidly as soon 
as oil gets between the contact surfaces. 

Some kind of vegetable fibre, made into a 
paper or mill board, seems to be the preferred 
material, and it is common to treat such paper 
with a tarry composition, which tends to raise 
the co-efficient of friction, as well as to render 
its value more nearly constant under the influ¬ 
ence of water and oil. 

The non-metallic friction face is the one worn 
out in service, or at least it wears the more rap¬ 
idly. This part of the combination, though of 
limited life, can be renewed at a comparatively 
small expense, and it fails only after giving due 
notice. It is the practice to make the disc face 
metallic, and the friction wheel rim non-metal¬ 
lic. Great care should be exercised in starting 
the car, as at such times the disc is liable to 
slip at speed upon the rim of the friction wheel 
which is then either stationary or revolving 
very slowly, and flat spots may very easily be 
w T orn upon its surface. 

The Planetary Change Speed Gear. This 
system of transmitting the power at various 
speeds comprises a high-speed connection for 
the direct drive, and an arrangement of gears 
that reduces or reverses the motion when one 
or another drum on which these gears or pin¬ 
ions are mounted is held stationary. Most 
planetary systems give only two forward speeds, 
and the reverse, but in some instances they are 
made to give three forward speeds. They are 


188 


The Automobile Handbook 


used chiefly pn small automobiles, or runabouts; 
but when cheapness of construction is an object 
they are sometimes employed on touring cars. 

In Fig. 90 is shown one form of planetary 
system. The gear a is the only one keyed to 



the engine shaft b. The gears c, d and e all 
mesh with the gear a, and are made long enough 
to extend beyond a and mesh with the gears 
f, g and h in pairs. The last three gears in 
turn extend beyond the gears c, d an^ e, and 





The Automobile Handbook 


189 


mesh with the gear i, which is keyed to a sleeve 
connected to the drum j. The gears c, d, e, f, 
g and h turn on pins fastened to the drum k, 
but only the gears c, d and e mesh with a, and 
only f, g and h mesh with the gear i which 
turns loosely on the shaft b. The internal gear 
1 meshes only with the gears c, d and e, and 
is rigidly connected to the sprocket m that 
drives the automobile. The cover n is attached 
to the face of the drum k by means of screws, 
thus forming an oil reservoir that keeps the 
gears well lubricated w T hen the automobile is 
running. There are separate brake, bands 
around the drums j and k, and a friction disc 
keyed to the shaft just outside of the drum j. 

When the friction disc is pressed against the 
drum j, the gear is held so that it must turn 
with the shaft; consequently, the entire me¬ 
chanism is locked together and the sprocket m 
turns at its highest forward speed. If now the 
friction disc is released and the brake band 
around the drum j is applied so as to hold it 
from turning, then the gear a turns the gears 
c, d and e, causing them to turn the gears f, 
g and h; but, as the gear i is held stationary 
with the drum j, the gears f, g and h, and also 
the drum k, to which they are attached, must 
revolve around the gear i in the same direction 
as the shaft turns, but more slowly. The gears 
c, d and e turn on pins that are fastened to the 
drum k; consequently, they revolve with it as 
they turn on their axes and thus cause the in- 


190 


The Automobile Handbook 


ternal gear 1 and the sprocket m to turn in the 
same direction as the shaft. This gives the slow 
forward speed. 

When the drum j is released, and the drum k 
is held by a brake band, the gears c, d and e 
are caused to turn on their pins, and conse¬ 
quently drive the internal gear 1 in a direction 
opposite to that of the engine shaft, driving the 
automobile backwards. WTien the brake bands 
and friction disc are all free from the drums, 
the gears turn idly, and if the engine is running, 
no motion is transmitted to the sprocket and 
the automobile stands still. 

Ford Planetary Change Gear. The gears 
in the Ford transmission are arranged as shown 
in Figure 91 and all of these sets revolve around 
the main shaft. This device uses all spur gears, 
that is, gears having external, rather than 
internal, teeth. As in other planetary drives 
the speed ratios are secured by stopping the 
movement of certain gears which are carried 
on parts attached to cylindrical drums. Bands, 
similar to brake bands, act on these drums to 
stop their rotation, the tightening of any band 
stopping its corresponding drum and bringing 
the required gears into action. 

Mounted with their centers in line with the 
main shaft of the transmission and in line with 
the crankshaft of the engine are three gears, 
two of which are attached to two separate drums 
while the third is called the driven gear and is 
attached to the shaft through which the rear 


The Automobile Handbook 


191 


axle is driven. These three gears vary in size 
but are all fastened together so that they rotate 
at the same rate of speed and as a unit. In mesh 
with these gears and spaced equi-distant around 
their circumferences are three sets of three 
gears each. 

When it is desired to start the car from a 
standstill, a pedal is pressed which causes one 



of the drums to stop revolving. This drum is 
attached to one of the gears of the three on the 
main shaft. The pins or axles of the three sets 
of three gears are fastened to the flywheel of 
the engine so that when the engine is running 
the sets of gears are carried around on the outer 
edges of the gears which are mounted concentric 
with the shaft. Because of the fact that the 















192 


The Automobile Handbook 



one gear being held by the band and drum is 
standing still, the sets of three gears must turn 
around their own centers in traveling around 
the outside of this center gear, and, depending 
on the relative sizes of the stationary gear and 
the gears traveling around it, a motion is 
imparted to the driven gear on the shaft, winch 
may be either forward or backward. 


Fig. 92 


CHANGE SPEED, SLIDING GEAR TYPE. 

A form of change speed gearing that is in 
use on a large majority of cars is that known 
as the sliding gear. All sliding gear trans- 







The Automobile Handbook 193 

missions consist of two principal shafts lying 
parallel to each other and placed one above the 
other or side by side. Each shaft carries a 
series of gears, those on one shaft being per¬ 
manently fastened against lengthwise move¬ 
ment, while those on the other shaft are capable 
of being moved along the shaft while turning 
with it. This latter set of gears is built with 
either a square or key-wayed hub and the shaft 
on which the set slides is made square or with 
spline keys to correspond. The gears on the 
other shaft are made of such sizes that when 
the sliding members are moved they come into 
mesh with the gears on the other shaft so that 
when together they form pairs, that is to say, 
when a gear on one shaft is in mesh with one 
on the other shaft it is impossible to cause 
any other gears to mesh at the same time. 

The gears are graduated in size so that the 
several pairs or combinations that may be 
formed vary in ratio, and in this way it is pos¬ 
sible to obtain different degrees of speed reduc¬ 
tions between the two shafts and therefore 
between the engine and road wheels. 

In forms of construction that use the two 
shafts exactly as described in the previous para¬ 
graphs, and in which one shaft is connected 
through the clutch to the engine and the other 
one through the drive parts to the rear wheels, 
the series of sliding gears is made with all of 
the gears fastened together so that there can be 
no relative motion between them, and in this 


194 


The Automobile Handbook 



Fig. 93 

Selective Sliding Change Speed Gears 














The Automobile Handbook 


195 



case the entire sliding member is moved bodily 
along the shaft. This particular form is known 
as a progressive sliding gear. It is necessary, 
with this type of construction, to pass from one 
ratio to another in the same order for each 
operation, and if it is desired to pass from the 
extreme low ratio to the highest ratio, it is nec- 


Fig. 94 

Selective Sliding Gear With Disc Clutch in a 
Unit Power Plant. A, Clutch Shaft. B, Clutch 
Shaft Gear. C, Countershaft Gear. D, Second 
Speed Gear. E, Low Speed Countershaft Gear. 
F, Second Speed Sliding Gear. G, Low and Re¬ 
verse Sliding Gear. H, Sliding Gear Shaft.. 
essary to pass through all intermediate ratios. 
The progressive form of transmission is no 
longer fitted to cars and an extended descrip¬ 
tion is not considered necessary 










































196 


The Automobile Handbook 


The type of sliding gear transmission that 
is most popular is called the selective sliding 
gear and with the exception of some important 
modifications is similar in operation and con¬ 
struction to the progressive type already de¬ 
scribed. Selective sliding gears are shown in 
Figs. 92 to 97 and the following description 
will apply more or less to all of them although 
the form shown in Fig. 94 is specifically cov¬ 
ered. It will be noted that the clutch is at the 
left hand end of the illustration, and through 
this clutch the power of the engine is trans¬ 
mitted to the shaft marked A. At the right 
hand end of the shaft A is carried a gear B, 
and this gear is in mesh with the gear C on 
the lower shaft of the transmission, it will there¬ 
fore be seen that whenever the clutch causes 
shaft A to revolve, gears B and C will also. turn, 
and inasmuch as C is fastened solidly to the 
lower shaft of the transmission, this lower shaft 
will turn whenever the engine is running and 
the clutch engaged. The upper shaft in the 
transmission marked H is not made in one piece 
with shaft A, but its left hand end is made of 
a diameter sufficiently small to fit into a recess 
in the shaft A and in the hub of the gear B. 
This construction simply provides a bearing for 
one end of the shaft H so that it may revolve 
independently of shaft A. Shaft H is formed 
with four longitudinal keys integral, and on 
this shaft are mounted the gears F and G with 
their hubs formed with keyways to engage 


The Automobile Handbook 


197 


the keys on shaft H. This construction allows 
the gears F and G to be moved lengthwise while 
turning with the shaft. Gears D and F are 
made of such diameter that when F is moved 
to the right it meshes with D and gears E and 
G will mesh when G is moved to the left. The 
right hand end of shaft H is fastened to the 
universal joint that leads to the rear axle. 



Sliding Gear Set for Separate Mounting 
The operation is as follows: With the en¬ 
gine running and the clutch engaged, power 
is transmitted through gears B and C to the 
lower shaft of the transmission, and inasmuch 
as gear C is larger than B, the lower shaft 
will run at a lower rate of speed than the clutch 
shaft. If now the gear G be caused to mesh 
with E, the shaft H will be revolved but at a 
still lower rate of speed than the bottom shaft. 























198 


The Automobile Handbook 


and inasmuch as H drives the rear axle it will 
be seen that the mechanism has given a positive 
drive at a speed much below that of the engine. 



Heavy Duty Selective Sliding Gear for Rear Axle 
Mounting 

When it is desired to secure a^higher speed 
of the car relative to that of the engine, gears 







































































The Automobile Handbook 199 

G and E are withdrawn from each other and 
gear F is moved into engagement with D. It 
will be noted that gears D and F are approxi¬ 
mately the same size, and the upper shaft will 
then turn at a speed very nearly the same as 
that of the bottom shaft, but still less than 
the speed of the engine. This position is known 
as second speed or intermediate speed. 

When it is desired to secure a still higher 
ratio of speed it is done by moving gears D and 
F out of engagement and then moving F to 
the left. Gear F carries one-half of a jaw, or 
toothed clutch, and gear B carries the other 
half of this same clutch. It will thus be seen 
that when F and B are together the clutch will 
be engaged and shaft A will drive shaft H at 
the same speed at which A is revolving. This 
provides high speed or direct drive. 

When it is desired to reverse the direction of 
motion of the car, gear G is moved into engage¬ 
ment with an idler gear that is not shown, and 
this idler gear is driven through another one 
on the bottom shaft of the transmission. The 
idler gear being interposed between the upper 
and lower transmission shaft gears causes the 
upper shaft to reverse its previous direction 
of motion. 

Certain variations of selective sliding gears 
are in use, one of which is shown in Fig. 
97. In this particular form the spur gears 
remain in mesh at all times, but neither set 
is keyed to its shaft. Between the gears are 


200 


The Automobile Handbook 


mounted jaw clutches, and these clutches are 
keyed to the shaft. In place of moving thi 
gears into or out of engagement, the jaw 
clutches are moved, and depending on which 
clutch is moved and which way it is moved, 



Fig. 97 


Individual Jaw Clutch Sliding Gear Set 
the several sets of gears may be successively 
used, providing speed ratios similar to those 
in other forms of selective sliding gears. 

Transmission of Power—Efficiency of. 

Two-chain drive, from motor to speed-change 
gear, from speed-change gear to rear axle—75 
per cent. 

Quarter-turn or right-angle drive, with dou¬ 
ble-chain drive to free rear wheels—70 per 
cent. 

Longitudinal shaft drive, with universal 
joints and bevel gear in differential case—65 
per cent. 

Gearless Transmission. ' This name has been 
applied to a wide variety of transmission, or 
change speed devices. It is quite customary to 






















The Automobile Handbook 


201 


refer to the friction drive as a gearless sj^stem, 
and this is true to the extent of not using 
toothed gearing of any form. 

A car using this name was built several years 
ago, and its construction embodied a novel 
method of change speed mechanism. The trans¬ 
mission system of the gearless car made use of a 
central cone, long in proportion to its diameter, 
and faced with friction material. Placed so that 
they might engage with this driving member, 
were several sets of rollers, which were, in turn, 
brought into contact with driven members or 
clutches. The principle of operation was that 
of the planetary, or internal epicyclic, gear. In 
place of using toothed gears, this car secured its 
drive by bringing one or the other sets of rollers 
into play and thereby secured three forward 
speeds and one reverse. Large power was trans¬ 
mitted and little trouble found. 

Magnetic Transmission. 

The difference between a car with magnetic 
transmission and other gasoline cars lies only 
in this transmission. There is no change in the 
engine or its operation. There is no change 
in the driving parts, save as regards their con¬ 
nection with the power. The parts omitted 
are the clutch and the clutch pedal, gears and 
shifting lever, flywheel, starter and lighting sys- 
tern, this one transmission unit taking the place 
of all. There is no mechanical connection be¬ 
tween the engine and the driving shaft. This 


202 


The Automobile Handbook 



Fig. 98 

The Owen Magnetic Transmission 


srNtfcMOfr m °to r 

































































































The Automobile Handbook 203 

control also embodies an electric brake, and an 
automatic electric sprag, which absolutely pre¬ 
vents the car backing down hill, even though 
the motor is stalled. Should the engine be 
stalled on a hill, the car can be held without 
use of the brakes by simply moving this con¬ 
trol lever into high speed position. 

The power is never disconnected from the 
driving wheels of the car from the moment of 
starting up to the highest speed. 

The electrical apparatus consists of two units, 
Fig. 98, contained in a one-piece construc¬ 
tion : the one nearest to the engine has its mag¬ 
netic field pieces keyed to the engine crank¬ 
shaft and acts as a flywheel to the engine. Its 
armature is mounted on the propeller or drive 
shaft, hence it will be seen that both these parts 
can revolve. The second unit of the apparatus 
has stationary magnetic fields and its armature, 
as in the first case, is mounted on the propeller 
shaft. The first unit becomes in turn a 
dynamo, magnetic clutch and a motor, the sec¬ 
ond unit, a motor and dynamo. 

A controller, with resistance coils internally 
contained, is bolted to the chassis frame for¬ 
ward of the dash, alongside of the engine, and 
is operated by a lever on the steering wheel 
through a small gearing at the bottom end of 
the steering column. 

By placing the control lever in the position 
“cranking,” a battery is connected through 
the first unit, which in this instance becomes 


204 The Automobile Handbook 

a motor, and once the engine is cranked, the 
lever can be placed in the “neutral” position 
until ready to start the car. 

On moving the control lever to the first po¬ 
sition, turning effort is produced by weak¬ 
ening, with a shunt resistance, the field of 
the first unit, which becomes a dynamo, and 



Principle of the Magnetic Transmission: A, En¬ 
gine Crankshaft. B, Revolving Field. C, Sta¬ 
tionary Field. D, Front Armature. E, Rear 
Armature. F, Propellor Shaft. 

the current generated, due to the electrical, 
slip between the magnetic fields and the arma¬ 
ture, is fed to the second unit, which, acting 
as a motor, produces a powerful starting torque. 
At the same time the pull of the magnetic fields 
of the first unit acts as a magnetic drag on its 
armature, and thus two forces assist in rotat¬ 
ing the propeller shaft, which, through the bevel 
drive, communicates power to the road wheels. 

The second position of the control lever cuts 
the resistance out of the first unit (dynamo) 
field and shunts through a high resistance some 
of the field current in the second unit (motor), 
thereby increasing the speed of the car. 


























The Automobile Handbook 205 

In the third, fourth and fifth control lever 
positions, the second unit (motor) field is suc¬ 
cessively weakened until in the sixth control 
lever position, the field current is almost en¬ 
tirely shunted, so that previous to placing the 
control lever in the seventh (and last) position, 
the second unit is practically of itself not do¬ 
ing any work, apart from the fact that there 
is very little slippage between the first unit 
(dynamo) field and armature, resulting in gen¬ 
erating of but small current. In other words, 
the drive shaft is being carried around almost 
entirely by the magnetic drag of the first unit’s 
field on its armature. It will hence be seen that 
there is an electrical balance in effect through¬ 
out the entire sequence of operations. 

On placing the control lever in the seventh 
position, the first unit becomes what may be 
termed a “magnetic clutch / 7 the armature 
and field are closed-circuited, and an almost 
negligible slip only is required to generate suf¬ 
ficient current to enable the field to drag its 
armature around with it. 

The second unit with the control lever in 
high speed position becomes a generator, and 
when the car is running, charges the lighting 
and starting battery with a predetermined 
charge. 

From this point on the entire control is 
brought about by accelerating or decelerating 
the gas engine, the armature of the first unit 
follows its magnetic field promptly, generating 


206 


The Automobile Handbook 


of its own accord whenever necessary more cur¬ 
rent and hence getting more magnetic drag to 
bring it up to the same speed as the magnetic 
fields. Thus, so long as the control lever 
is in any position other than neutral on ac¬ 
celerating, an increase of speed is obtained, 
but on decelerating, the car coasts just like an 
ordinary car with the clutch released. This is 
brought about by the armature of the first unit 
traveling faster than the fields, and thus not 
generating any current until such a time as 
the car comes back to the speed, where the arm¬ 
ature of the first unit is traveling at the same 
or slightly lower speed than the field pieces 
or the engine, when again current is generated 
and the drive taken up as before. 

Should excessive grades be encountered where 
extra torque may be desired, the placing of the 
control lever in a lower position will give the 
desired result, and naturally by increasing the 
engine speed with the control lever in a lower 
position than high, more current will be gener¬ 
ated, due to the extra electrical slip, and thus 
give added torque. 

At neutral position the maximum electrical 
braking effect is obtained. Here the first unit is 
open-circuited and the second unit closed-cir- 
cuited and the magnetic braking reaction brakes 
the car to 10 miles per hour, below which speed 
the armature does not revolve within the motor 
field fast enough to create the braking effect, 
thus automatically holding the car on a grade at 
about the above speed. 


The Automobile Handbook 207 

Chassis. The word chassis since its adoption 
into the English language, is taken to mean the 
frame, springs, wheels, transmission and in fact 
all mechanism except the automobile body. In 
its original French it does not mean all this, but 
is strictly restricted to mean the frame, or the 
frame and springs. 

Chauffeur. This term when literally trans¬ 
lated means the stoker or fireman of a boiler. 
The use of the word has been extended to the 
operator of a motor car, but does not usually re¬ 
fer to the paid driver, who is generally known 
as the mechanician or mechanic. 

Clutch. Clutches may be classified as fol¬ 
lows : a, cone; b, disc; c, band; cone clutches 
may, in turn, be subdivided as follows: a, metal 
to metal; b, leather faced; c, cork insert; while 
disc type may be classed as: a, leather faced; 
b, multiple disc; c, cork insert; and band 
clutches may be put down as of the a, constrict¬ 
ing, b, spiral, or c, expanding types. Clutches, 
of whatever type or class, have but one prime 
object, i.e., to enable the operator to start and 
stop the car without having to stop the motor. 
There is a secondary consideration, if we take 
into account the fact that it is convenient to be 
able to slip the clutch, on occasion. Some types 
lend themselves to this secondary purpose with 
greater facility than others, and it is also true 
that some clutches are most easy of application, 
all things considered. 

As clutches are at present designed, the ques¬ 
tion is, can slipping be tolerated? or, can 


208 


The Automobile Handbook 


clutches be slipped to control the speed of a 
car? It is believed not. The average clutch 
has very little of the character of the average 
braking system, and when it comes to brakes 
they do not last so long that it is desirable to 
wear them out sooner than they will naturally 
need replacement. In other words, it seems 
quite out of the question to consider the 
clutches of today as suitable for the double pur¬ 
pose of clutching and speed controlling, by way 
of slipping the clutch at will. It is not uncom¬ 
mon to hear autoists talking of the multiple 
disc clutch as one that undergoes little or no 
deterioration as a result of continuous slipping 
under variations of load. 

They seem to think that the large surface ex¬ 
posed, especially in view of the fact that the 
discs are submerged in oil, will prevent damage 
if the clutch is caused to slip. They forget that 
the discs are thin, and also that they are loose 
on the splines, keys, or feathers that prevent 
the discs from rotating. No member keyed onto 
a shaft will stand much abuse. This is espe¬ 
cially so, if the member has but little bearing 
surface on the key. Even a considerable num¬ 
ber of such members working in unison will 
fail to stand up under the work because the 
joint is not firm. Lost motion is bound to re¬ 
sult in more lost motion in a short while, and 
in a multiple disc clutch the discs soon fray out 
and interfere with each other, and with the 
clutching functions, within a space of time so 


The Automobile Handbook 


209 


short as to surprise even those most experi¬ 
enced in the use of this type. 

Band Clutch. A band, or friction ring, 
clutch, is shown in Fig. 100. The wheel which 
is connected to one of the shafts is shown at a, 
and the band, or ring which is connected to the 
other shaft and which is made in two parts, is 
shown at b and c. At d and e are curved arms 



Fig. 100 

pivoted at f and g. The links h and i connect 
these curved arms to the parts b and c of the 
band. By means of a fork, and tapered sleeve, 
not shown, the ends j and k of the arms are 
forced apart when the clutch is brought into 
use. This throws toward the shaft the ends 1 
and m of the levers d and e, and brings the two 
parts b and c of the clutch ring in contact with 






210 


The Automobile Handbook 


the friction or driving surface of the wheel a, 
which is thereby forced to turn with the driving 
shaft. The band clutch has had many expo¬ 
nents in the motor car art, but is open to cen¬ 
trifugal effects to such an extent that it re¬ 
quires considerable ingenuity to overcome trou¬ 
bles arising therefrom. At high engine speeds 
the operating levers have been so arranged as 
to lower the normal expanding pressure. 



Fig. 101 


Cone Clutch. There are a number of modi¬ 
fications of this type of clutch, the general prin¬ 
ciples of which are illustrated in Fig. 101. The 
flywheel a is secured to the shaft b by means 
of bolts through the web of the wheel. At c is 
an expansion ring into which the friction cone 
d fits. The helical spring e holds the cone 
against the expansion ring with the required 






















The Automobile Handbook 


211 


amount of force. At f is a ball bearing that 
takes the end thrust when the cone is pulled 
away from the expansion ring. 

The arms g are coupled to the shaft that turns 
with the friction cone. Ordinarily the two parts 
of the clutch are held together by the pressure 
of the spring, and when it is desired to discon¬ 
nect the cone, a foot pedal is forced down so 
as to act on a fork and sleeve and pull the cone * 



away from the expansion ring. When the pedal 
is released, spring e forces the clutch into action 
again. 

Fig. 102 is a sectional view of a form of 
leather faced cone clutch in which the male part 
of the cone moves axially toward the engine. 
Fig. 103 shows a clutch constructed on the 
same principle, but in place of having one 
strong actuating spring surrounding the axis, 
it has three weaker spiral springs near the pe- 
















212 


The Automobile Handbook 


riphery of the male member. Fig. 104 is a verti¬ 
cal section of a clutch suitable for a 50 H. P. 
car. The cone angle is 13 degrees, and the di¬ 
ameter 16 inches, with a total frictional area of 
128 square inches, the axial pressure resulting 
from the spring being 375 lbs. A small spiral 
plunger spring A under the leather face B 
causes it to pick up the load more quietly and 
smoothly. Fig. 105 illustrates an early form 
of clutch intended for a car of about 20 H. P. 
One form of toggle joint is also shown at A. 



Fig. 103 


This clutch also has multi-springs for creating 
the proper frictional contact, and a peculiar 
form of spring application simple in the ex¬ 
treme. A multi-cone clutch is shown in section 
in Fig. 106. Its action is as follows: When the 
clutch engages, the smallest cone seizes first, 
commences to revolve and subjects the spiral 
springs between the next two clutches to tor¬ 
sional movement, which draws them together 
and brings the two outer cones into action; the 
idea being that the small clutch shall slip, tend 





The Automobile Handbook 


213 


to accelerate the car, that the medium clutch 
shall behave in a similar manner and that when 
the large clutch comes into play the three com¬ 
bined pick up the load and move the car. 

The so-called inverted cone is well illustrated 



in figure 107. The reversed cone is contained 
in an extension A, built onto the flywheel B. 
When the cone is disengaged it moves toward 
the engine, exactly reversing the action of the 
foregoing type. This clutch has its adherents, 















































214 


The Automobile Handbook 


and it is a good one, differing very slightly, if 
properly assembled, in its efficiency from the 
direct-acting cone. It may be kept free from 
dirt and oil much more perfectly than in the 
other form. 

Disk Clutch. A clutch of the multiple-disc 
type is shown in Fig. 108. A two-arm spider 
a, keyed to the shaft b, serves to hold in place a 
number of metal discs c, between which are 
other metal plates d held on the sleeve e by 
means of a key f. The sleeve e is in turn keyed 



Fig. 105 


Fig. 106 


to the shaft g, and to it is screwed a ring h 
having three pairs of lugs carrying three levers i, 
with rollers j at their outer ends, as shown. The 
other ends of the three levers press against the 
plate k when the clutch is engaged by an in¬ 
ward movement of the collar 1, plate k being 
free to move along the key f. Discs c are free 
to move longitudinally on the arms of the spi¬ 
der a, and also on sleeve e, around which they 
rotate when the clutch is out of engagement; 
but the arms of the spider, fitting into slots in 
the discs, cause them to rotate with the shaft b. 

















The Automobile Handbook 


215 


The plates d are free to move longitudinally on 
the key f in the sleeve e; and since the sleeve is 
keyed to the shaft g, it is evident that, when 
in engagement with the discs c, the, plates d 
must cause the shaft g to turn with the shaft b. 
The discs c and plates d run in an oil bath, 



obviating wear of the plates and discs. These 
are brought together forcibly by throwing the 
cone faced end of the collar 1 against the rollers 
j, thereby causing the ends of the three levers i 
to press the plates and discs together with suf¬ 
ficient force to cause the shafts b and g to rotate 
as one shaft. 
























216 


The Automobile Handbook 


Five-plate Clutch. In the matter of the num¬ 
ber of plates in the disc clutch there is no agree¬ 
ment between designers. Some use a very large 
number of thin plates, as many as fifty or sixty, 
and others use a very small number, as few as 
six or eight; in fact, it may be said that the sin¬ 
gle disc clutch, which has only two frictional 



Fig. 108 

Five-Plate Clutch 

surfaces, is the lower limit. One arrangement 
which uses five plates is shown in Fig. 108. The 
diameter of the clutch is somewhat smaller 
than that of the single or three-plate types, but 
its diameter must be quite large in order to 
transmit considerable horse power. 

Clutches are made with various numbers of 
plates, from three to more than sixty, depending 
on the work required and the size and material 




























































The Automobile Handbook 


217 


of which the plates are made. Plate materials 
include hardened steel for both members, steel 
and bronze, steel with cork inserts, and steel 
covered with some friction material similar to 
brake lining. 

Disc clutches using steel to steel are operated 
in a bath of oil. Those using bronze and steel 
may or may not operate in oil. As a general 
rule, clutches that are not enclosed are fitted 
with cork or an asbestos composition as the fric¬ 
tion material. However, either of the forms just 
mentioned operate satisfactorily in an oil bath, 
and it is, therefore, simply a question of choice 
with the designer. Unenclosed clutches are 
called “ dry-plate clutches/ ’ 

Clutch Troubles. One of the greatest 
sources of trouble for the novice lies in the 
clutch. This may be just right, it may be slip¬ 
ping, or it may be what is called fierce. The sec¬ 
ond manifests itself in such pleasant situations 
as climbing a hill when, with the engine run¬ 
ning at its highest speed and the proper gear 
engaged, the car starts to run backward instead 
of forward. Or on the level, with the engine 
racing and the high gear in, no speed results. 

The last condition shows itself in the sudden 
jumping forward of the car w r hen the clutch 
has been let in, or it may even be so severe as 
to shear off the bevel driving gear when used 
with studded non-skid tires or any form that 
will not slip easily. 

To repair the first, look at the leather, if this 


218 


The Automobile Handbook 


is all in good shape with an apparently good 
surface, but has lubricating oil on it, wash the 
surface well with gasoline. It is not a bad idea 
to roughen the surface of the leather a little 
with a coarse file. 

The harsh or fierce clutch is remedied by the 
application of a proper oil for this purpose. 
Castor oil is universally used and a good way is 
to soak the complete clutch in it over night. 
This will cure a case of harsh leather, but it 
may be that the trouble is only a lack of adjust¬ 
ment of spring tension. Usually there is an ad¬ 
justing nut and a locking nut. Back off the 
latter and make an adjustment. Then tighten 
the lock nut to retain it. For the beginner, it 
is better to adjust a little at a time and make 
several successive jobs of it than to try to do 
it .all at once. But always adjust it as soon as 
possible. 

The leather of the ordinary cone clutch by 
degrees acquires a sort of coarse surface glaze, 
-which may or may not represent actual charr¬ 
ing of the leather, but is certainly due to the 
slipping it experiences. A leather with its sur¬ 
face so glazed has a very harsh action, since the 
surface is so hard that it grips all at once. The 
glazed surface -will not absorb oil to any appre¬ 
ciable extent, a fact which is easily seen on at¬ 
tempting to dent the surface with a thumb nail 
after giving the oil time to soak in. In this con¬ 
dition the best thing to do is to put on a new 
leather. Unless the angle of the cone is too 


The Automobile Handbook 


219 


abrupt, a piece of ordinary belting will serve 
the purpose, provided it is of uniform thickness 
throughout. The belting may be soaked in 
neatsfoot oil over night before applying, and 
this will render it pliable enough to take the 
shape of the cone. If the old leather is retained 
in service it becomes almost essential to squirt 
a litt-le oil on it every day or two, as otherwise 
it may take hold with such a jerk as to'endan¬ 
ger the transmission shafts. If the cone re¬ 
leases by drawing backward, there are proba¬ 
bly openings in the web of the cone through 
which the spout of a squirt can may enter. Oil 
squirted into the flywheel interior will then 
quickly find its way to the dutch surface. 
Sooner or later, however, the leather will be¬ 
come glazed so smooth that it will not hold at 
all, and it is then liable to slip and burn up 
without warning. There are few things more 
exasperating than a clutch which cannot be 
made to hold properly, particularly when the 
car happens to be covering a bad stretch on 
which every available bit of power that can be 
transmitted to the rear wheels is necessary. The 
use of emergency remedies under such circum¬ 
stances most often leads to the necessity for 
clutch repairs, as road dirt and grit are not the 
best things possible for the leather facing, and 
frequently no other friction producing com¬ 
pound is to be had at the time. 

Renewal of Leather on Cone Clutch. Re¬ 
move the old leather by cutting off the rivets 


220 


The Automobile Handbook 


on the underside, and driving the rivets through 
to the outside. Keep the old leather and use 
it as a pattern by which to cut the new piece. 
It will be much better, however, to purchase 
from the factory a new leather of the proper 
width and thickness. As a new leather will 
have considerable “give,” it must be stretched 
tightly over the cone. First cut one end of the 
leather square and fasten it to the cone with 
two rivets. The other end should not be cut at 
this stage of the work, but brought around to 
meet the fastened end, and, after tightly 
stretching it over the small end of the cone, 
fasten it with a single rivet. Then' force the 
leather up onto the cone, drill out and counter¬ 
sink the holes and rivet up securely. The only 
knack in the operation is to keep the leather 
tight that it may be a snug fit on the cone. A 
loose leather will, naturally, be a dead failure. 
After the leather has been forced into its place 
the uncut end should be trimmed to make a 
good joint. Any unevenness may be trued up 
with a file. The new leather will readily ab¬ 
sorb several applications of castor oil before it 
becomes smooth and pliable. 

Care should be taken that the rivet heads are 
countersunk below the surface of the leather. 
In case they work flush, owing to the wearing 
down of the leather face, they should be riv¬ 
eted. The “biting” or jerky action of a cone 
clutch may often be traced to the rivets work¬ 
ing out, and this will frequently prevent the 


The Automobile Handbook 


221 


clutch from being readily disengaged. Rerivet¬ 
ing will prove an effective remedy in this case, 
and considerable additional service may be had 
from the leather before it wears down to the 
rivet heads. 

The oil used in multiple disc clutch housings 
should be changed at frequent intervals. The 
same lubricant as used in the engine is suitable 
for warm weather driving, while for cold weather 
the oil may be diluted by the addition of one- 
fourth to one-third kerosene to avoid dragging. 
The clutch housing should be filled to a point 
a little below the center line of the shaft. 

Dry disc clutches require little care other than 
being kept reasonably free from dirt and accu¬ 
mulations of grease and oil. Their thrust release 
bearings should be given regular attention and 
kept properly lubricated with cup grease or 
heavy oils. 

Compression. Normal compression in any 
given design of motor would be the compres¬ 
sion (cold) fixed by the designer by the rela¬ 
tion of the sweep of the piston to the clearance 
space. Normal compression is not the same, as 
measured in pounds per square inch, in all mo¬ 
tors. The normal compression as against loss 
of compression would be evident to a motorist 
in the act of cranking. Were the compression 
to become abnormal, as a result of carbon de¬ 
posit, it would be rendered manifest by knock¬ 
ing on a gradient, or by way of pre-ignition. 

Compression, How to Calculate. The com- 


222 


The Automobile Handbook 


pression in atmospheres of a motor may be read¬ 
ily found by dividing the cubic contents of the 
piston displacement by the cubic contents of 
the combustion chamber in cubic inches, and 
then adding one to the result. 

To ascertain the compression in atmospheres 
of a motor, when the cubic contents of the com¬ 
bustion chamber are known: Let S be the 
stroke of the piston in inches and A the area of 
the cylinder in square inches. If C be the con¬ 
tents of the-combustion chamber in cubic inches 
and N the required compression in atmospheres, 
then 

S’ X A 

N= - +1 

C 

Example: Find the compression in atmos¬ 
pheres of a motor of 4-inch bore and 6-inch 
stroke, whose combustion chamber has a capac¬ 
ity of 18 cubic inches. 

Answer: Six multiplied by 12.56 equals 
75.36, which divided by 18 gives 4.19, and 4.19 
plus 1 equals 5.19, or the compression in at¬ 
mospheres required. One atmosphere = 14.75. 

If it is desired to ascertain the compression 
in atmospheres of a motor, the combustion 
chamber of which is of such shape that its di¬ 
mensions cannot be accurately calculated, its 
cubic contents may be found by filling the com¬ 
bustion chamber with water, and after remov¬ 
ing the water, ascertaining its weight in ounces, 



The Automobile Handbook 


223 


and then multiplying the result by 1.72. This 
gives the capacity of the combustion chamber 
in cubic inches. The compression of the motor 
can then be readily calculated from the for¬ 
mula given herewith. 

Compression, How to Test for Leaks in. To 
discover if there are any leaks in the compres¬ 
sion of a gasoline motor, a small pressure gauge 
reading up to 75 pounds should be fitted into 
the spark plug opening in the combustion 
chamber by means of a reducing bushing. When 
turning the starting crank of the motor slowly 
the gauge should indicate at least 60 pounds 
per square inch if the compression is in good 
condition. 

To test for leaks, fill a small oil can with 
soapy water and squirt round every joint where 
there may be a possible chance for leakage. Get 
an assistant to turn the crank and watch for 
bubbles at the joints. 

If the joints are all tight, next examine the 
condition of the admission and exhaust-valves 
and if either of them needs regrinding, it 
should be done, first with fine emery powder 
and oil, then finished with tripoli and water. 

When the valves have been ground to a per¬ 
fect fit, if the compression still leaks, the pis¬ 
ton rings should be examined, as the trouble 
will be found to be with them. 

Condenser, Use of. A condenser is used in 
connection with a Rumkorff, or jump-spark 
form of induction coil to take up or absorb the 


224 The Automobile Handbook 

static charge of electricity, occasioned by the 
self-induction, or electrical reaction in the pri¬ 
mary winding of the coil upon the breaking of 
the battery circuit by the interrupter or vibra¬ 
tor. This static charge is given up or dis- 



Fig. 109 
Condenser 


charged into the primary winding of the coil 
along with the battery current upon the closing 
of the circuit, thus intensifying the action of 
the secondary winding of the coil in a great de¬ 
gree. 

By absorbing the static charge of electricity 























































The Automobile Handbook 


225 


the condenser helps to decrease the spark or arc 
between the platinum contact points of the in¬ 
terrupter or vibrator, thereby lengthening the 
life of the platinum contacts by reducing the 
erosive action of the induced current spark. A 
jump-spark coil very often refuses to work 
properly on account of the condenser connec¬ 
tions having become loose. 

The capacity of a condenser is directly pro¬ 
portional to the area of the tinfoil sheets com¬ 
posing it, to the distance between the sheets, 
and to the inductive capacity of the dielectric, 
or separating medium. 

In condenser work it is the custom to cut the 
tin-foil sheets to some convenient rectangular 
shape, as shown in Fig. 112, each one with a 
neck so that all the + sheets can be soldered to¬ 
gether, on one side, and all the — sheets on the 
other. The dielectric paper is cut without 
necks, so that the necks of the tin-foil sheets 
can be readily contacted with each other, in 
such a. way, however, that the + sheets will 
not contact with the — sheets at any point. 
The paper is 1 inch wider than the tin-foil, so 
that the paper extends out for % inch all 
around, and beyond the tin-foil. In the illus¬ 
tration the top sheet of paper is removed to 
show the shape of the tin-foil sheets, and it will 
be observed that all the tin-foil sheets are of 
the same size, but they are so turned that the + 
sheets have their necks all to one side, while 
the — sheets have all their necks to the other 


226 


The Automobile Kmdbook 


side. Any number of sheets can be used, with 
the understanding that a sheet of oil-paper will 
be placed between adjacent tin-foil sheets, so 
that the + and — sheets will not contact with 
each other at any point. 

If the paper is pierced, or if the + an ^ — tin- 
foil sheets contact with each other, the con¬ 
denser will fail to perform its functions, and it 
sometimes happens that the sheets are punc¬ 
tured in service, thus rendering the condenser 
valueless for the intended purpose until the 
puncture is repaired, to do which requires that 
the fault be found, and a new sheet of paper 
substituted. 

Condensers are madq to fit into housings that 
allow of ready application on the instrument 
with which they are used. In many cases it is 
desirable to use a cylindrical form, while in 
others a rectangular outline may be permissible. 
Condensers of unusual form are often made from 
two long strips of tin foil, laid one upon the 
other, and separated by waxed paper or other 
insulating material. The long strip is then 
rolled or folded into the shape that is desired 
and the ends of the foil are attached to the con¬ 
denser terminals. 

A punctured or faulty condenser will cause 
the spark to be very weak and will also cause 
quite violent arcing at the breaker contacts, this 
arcing burning and pitting the contacts until 
they can no longer carry the current. The con¬ 
denser connections must always be secure. 


The Automobile Handbook 227 

Conductivity and Resistance. The following 

table shows the relative ability of various metals 
to conduct electricity and heat: 

Heat Electricity 


Silver. 

. 100 

100 

Copper.. 


99 

Aluminum. 

. 38 

63 

Brass . 


22 

Zinc . 


29 

Tin. 

. 14 

15 

Wrought Iron . 

. 12 

16 

Steel.. 

. 11.5 

12 

Cast Iron . 

. 11 

12 

Bronze. 

. 9 

7 

Lead. 

. 8 

9 


It will be seen that, in general, the conductiv¬ 
ity of a metal for either heat or electricity is in 
about the same relative proportion; that is, a 
good conductor of one is usually a good con¬ 
ductor of the other. 

A list of commonly used insulators with their 
relative ability to withstand electrical pressure 
is given below: 


Rubber, hard ... 

. 100 

Wax . 

46 

Paper, oiled .... 

. 100 

Paraffin. 

46 

Mica . 

. 92 

Rosin ... 

40 

Cloth, oiled .... 

. 80 

Glass .. 

32 

Rubber, india .. 

. 72 

Linen. 

26 

Celluloid. 

. 64 

Lava . 

24 

Porcelain . 

. 48 

Paper .. 

20 



























228 


The Automobile Handbook 


Cooling Systems. The cooling of a gasoline, 
or other automobile engine may seem a simple 
thing to the uninitiated, but in reality it is far 
from that and it is a fact that the deeper one 
goes into it, the more complex the situation be¬ 
comes. 

The cooling of internal combustion engines, 
in which category automobile engines come, is 
divided into two classes, viz., air cooled and 
liquid cooled. There are two reasons for cool¬ 
ing the cylinder walls. One is to permit of 
proper lubrication, and the other is to prevent 
pre-ignition. But it is advisable to allow the 
cylinder to work at as high a temperature as 
the lubricating oil will stand without carboniz¬ 
ing. The nearer the cylinder temperature can 
be kept to 350 degrees the more efficient will 
the motor be, speaking from the thermal stand¬ 
point, while on the other hand, mechanical effi¬ 
ciency may be sacrificed by too high tempera¬ 
tures. Therefore, a balance between the two 
should be established, and this course is usually 
pursued in practice. 

Air-Cooled Automobile Engines. The suc¬ 
cessful air cooling of an engine cylinder de¬ 
pends chiefly on an abundant flow of cool air 
over it. Some cylinders, however, are arranged 
to utilize a more rapid flow than others. Gen¬ 
erally speaking, the designer can take his choice 
between a comparatively plain cylinder surface 
over which a current of air can flow almost un¬ 
checked, and a cylinder with its heat-radiating 


The Automobile Handbook 229 

surface greatly multiplied by numerous pins, 
deep ribs, or other projections. These projec¬ 
tions increase greatly the radiating surface, but 
tend to obstruct the flow of air, although they 
aid in carrying away the heat. In the latter 
case, the velocity of the air stream does not 
need to be high, provided it is continuous: while 
in the former case, a constant and abundant 
supply of air is essential. 

Air-Cooling Systems. In modern automobile 
practice two systems of cooling are used—the 
air system and the water system, each of which 
has its adherents. As its name indicates, the 
air cooling system allows the air to strike the 
exterior of the engine cylinder, and thus carry 
off the excess of heat generated within it. To 
give the radiating surface, required for air 
cooling, the exteriors of the cylinders are either 
grooved or corrugated, or the surface of the cyl¬ 
inder is studded with metal pins or fins, so as to 
present as much surface to the outside air as 
possible. The object in the construction of all 
air-cooled motors is to make their external sur¬ 
faces offer as great a surface to the air as pos¬ 
sible, and to furnish these surfaces with as large 
a supply as possible. A fan is therefore used, 
driven by the engine itself, which constantly 
directs a current of fresh, unheated air upon 
the surface of the cylinder. 

The Franklin principle of air cooling is shown 
in Figure 110 and the details of the engine and 
air jacket construction are shown in Figure 111. 


230 


The Automobile Handbook 


The engine cylinders are fitted with vertical 
ribs and outside of these ribs is placed a sheet 
metal jacket. Air is taken in through the top of 
the jacket and passes down along the outside 
of the cylinders between the ribs, issuing from 
the bottom. 

Cool air enters through the front of the engine 
hood and passes to a compartment above the 
cylinders, this upper compartment being sepa¬ 
rated from the lower space by a sheet metal 
plate which fits tightly between the hood and 



Fig. no 

Franklin Air Cooling 


the jackets around the several cylinders. The 
only outlet for the air is then through the spaces 
around the engine cylinders, by means of which 
it passes to the lower compartment under the 
hood. 

From the lower compartment the air is 
exhausted by means of a turbine type of fan 
built as a part of the engine flywheel. Exhaus¬ 
tion of the heated air results in a continual flow 
through the cooling system at the rate of about 





The Automobile Handbook 231 

2200 cubic feet per minute at ordinary car 
speeds. 

It will be noted that none of the heated air 
from one cylinder touches any other cylinder, 
the t:>tal volume of entering air being divided 



Fig. ill 

Franklin Cylinder Jackets 

between the whole number of jackets in a fairly 
even flow. This system of cooling has been used 
on the Franklin car for a number of years and 
gives excellent results. 

















































232 


The Automobile Handbook 


Cooling, Water System of. The water cool¬ 
ing system includes the jackets around the upper 
parts of the cylinders and valve pockets, a radi¬ 
ator by means of which the heated water is 
cooled with a flow of air, a fan for maintaining 
the required air stream, a means for causing a 
circulation of water through the parts, either 
a pump or a natural thermo-syphon action, and 
the piping required to complete the water circuit. 

Water Circulation. There are two systems 
of water circulation in use for cooling the cylin¬ 
ders of explosive motors: The natural or ther¬ 
mo-siphon system and the forced water circu¬ 
lation. 

In natural or thermo-siphon water circula¬ 
tion the fact that cold water is heavier than hot 
water is taken advantage of. A head of water 
is obtained by placing the tank above the level 
of the cylinder water-jacket, and as the water 
in the jacket is heated by the combustion, the 
cooler water from the tank flows in, forcing the 
heated water in the tank to take its place, and 
in this manner an automatic circulation of wa¬ 
ter is set up. The pipes must be so arranged 
that they offer every facility for the free cir¬ 
culation of the water, the cold water leaving 
through a pipe at the bottom of the tank and 
entering at the lowest point of the cylinder, 
while the hot water leaves the top of the cylin¬ 
der and enters the tank at the side near the 
top. The water circulation, though automatic, 
is very slow, and for this reason requires a 


The Automobile Handbook 


233 



Fig. 112 

larger body of water to produce as good a cool¬ 
ing effect as a forced circulation. 

In forced circulation a rotary pump is used, 

















































234 


The Automobile Handbook 


the direction of the flow being such that the 
water passes from the pump to the cylinder, 
thence to the radiator, on to the tank, and then 
through the pump again, thus completing, its 
circuit. The water in this way gets the maxi¬ 
mum cooling effect from the radiator, and the 
bedy of water in the tank is kept cool. On ac¬ 
count of the high speed of a gasoline automo¬ 
bile motor, and the comparatively small amount 
of power required to circulate the water, ro¬ 
tary pumps are much used. As there are no 
valves to get out of order, and high speed is 
obtainable, this type of pump is very suitable 
for automobile use. 

In order that a thermo-syphon system may 
operate successfully, it is absolutely essential 
that the water passages around the cylinders, a£ 
well as the connections to the radiator, be of 
large capacity and perfectly free from obstruc¬ 
tions. Sharp bends should be avoided in every 
case. 

Pump, Water. The circulating pump is 
used in the belief that it affords a means for 
regulating the temperature of the jacket water 
supply, which would not always be the case 
with a thermal-syphon system. Such is not the 
case, as the pump, being driven direct from the 
motor, operates at a speed which varies with 
the motor speed. On starting the jiotor, it 
pumps cold water into the jacket. It pumps 
slowly at slow speeds, although the motor may 
be taking a full charge and heating rapidly. It 


The Automobile Handbook 


235 


pumps fast at high speeds, although the wind 
pressure and its consequent cooling effect may 





Center: Centrifugal Pump 
Bottom, left: Tubular Radiator 
Bottom, right: Cellular Radiator 
































































236 The Automobile Handbook 

be very great. If a circulating pump could be 
used in connection with a device to control the 
regulation of the motor temperature, the results 
would be more satisfactory. 

Pumps—Centrifugal. In this type of pump 
the height of lift is governed by the tangential 
force. Owing to this fact centrifugal pumps for 
use on automobiles may be made of aluminum 
for the housing, as it is both light and strong, 
fully able to withstand the pressure, there being 
no rubbing surfaces. The wheel, however, 
should be made of phosphor bronze of a good 
grade. In these pumps the suction inlet is 
usually at one side surrounding the axis, see 
Fig. 113. The pump should be geared to a speed 
as high if not higher than the crankshaft speed. 
The minimum peripheral velocity of the pump 
wheel should be 500 feet per minute. For au¬ 
tomobile service the general rule is to have a 
three vane wheel, and the curving is away from 
the direction of rotation. 

Overheating—Causes of. Overheating of the 
engine, when not traced to poor circulation, is 
almost always caused by too much gasoline. 
There are, how r ever, many possible causes of 
over rich mixture, some of which on the 
face of them might seem to be causes of lean 
mixture rather than rich. Prominent among 
these latter is too low a gasoline level in the 
float chamber due to the float valve closing too 
soon. The immediate effect of this is to make 
the mixture too lean at starting, and at low 


The Automobile Handbook 


237 


speeds. Starting is therefore difficult, and if 
the auxiliary air valve begins to' open at the 
usual motor speed, the mixture will again be 
' much too lean. These symptoms, however, un¬ 
less properly interpreted will probably lead the 
owner to increase the gasoline supply, or to ad 
just the spring tension of the auxiliary valve so 
that the latter will not open until quite high 
speed is attained. In other words, he adjusts 
to give a suitable mixture at one speed, and at 
other speeds the mixture is extravagantly over 
rich. It is well not to be too easily satisfied 
with the carbureter’s performance, as it may 
be found that one fault Such as the above has 
been imperfectly offset by another fault in the 
other direction instead of the correct adjust¬ 
ment being made where the fault really lies. A 
good carbureter will give a sensibly correct 
mixture at all speeds within the ordinary range 
of the engine. If it fails to do this the thing to 
do is to investigate until the trouble is found. 

Insufficient lubrication increases the friction 
between the piston and cylinder, and so gener¬ 
ates extra heat. Bad or unsuitable oil may 
have the same effect. 

Wear of the cams, tappets and valve stems 
may be the cause of overheating, as it would 
not require much loss from the faces of the va¬ 
rious moving parts that come in contact to 
cause a more or less appreciable difference in 
the operation of the valves, and as this wear 
tends to bring about a later action, it may be 


238 


The Automobile Handbook 


sufficient in the case of the exhaust valve to 
retain the burnt charge considerably beyond 
the time at which it should be allowed to es¬ 
cape. Where a motor runs at a speed of 800 
revolutions per minute or over, it will be evi¬ 
dent that it is a matter of very small fractions 
of a second. 

Another cause of overheating may be the de¬ 
posit of a fine film of scale on the inside of the 
circulating pipes and radiator. This scale is of 
a mineral nature, and, in addition to being an 
excellent nonconductor of heat, it is deposited 
in such intimate contact with the metal that the 
latter is practically insulated and its radiating 
power entirely lost. 

Overheating—Effects of. The immediate 
effect of overheating is to burn up the oil in the 
cylinders, or crank case. This causes a smell 
of burning, and an ordor of hot metal. There is 
sometimes a slight smoke and the motor will 
make a knocking sound. The cooling water be¬ 
gins to steam, and the car will gradually slow 
down and finally stop. 

The most serious cause of a stoppage on the 
road is overheating, which causes the lubricat¬ 
ing oil to burn up and the piston to expand and 
grip or seize in the cylinder. 

Overheating—Remedies for. As soon as any 
of the above symptoms are noticed: 

The motor should be stopped at once. 

Kerosene should be copiously injected into 


The Automobile Handbook 


239 


the cylinders and the motor turned by hand to 
free the piston-rings. 

The parts should then be allowed to cool. 

Do not pour cold water on the cylinder jack¬ 
ets, for fear of cracking them, but pour the wa¬ 
ter into the tank so as to warm the water before 
it reaches the cylinder jackets. 

A simple test in the case of an overheated 
motor is to let a few drops of water fall on the 
head of the cylinder. If it sizzles for a few mo¬ 
ments the overheating is not bad, but if the 
water at once turns into steam, the case is seri¬ 
ous. 

After the parts are cool, it will be advisable 
to put some oil in each cylinder. 

Anti-Freezing Mixtures. If a solution of al¬ 
cohol and water is used, the best results will be 
obtained by having it just strong enough to 
stand the lowest temperature to which it is 
likely to be subjected in the climate where it 
is to be used. 

The reason for this is that the alcohol evapo¬ 
rates out from the solution, and the stronger the 
solution, the more there is to evaporate, the 
easier it evaporates, and the greater the influ¬ 
ence of this evaporation upon the solution left. 

The diagram shown on page 33 indicates the 
freezing points of various solutions of dena¬ 
tured alcohol, also of wood alcohol. From this 
diagram a solution may be selected which will 
stand any temperature from 50° below zero to 
40° above. 


240 


The Automobile Handbook 


Other solutions may be made with calcium 
chloride (common salt), also the salts known as 
potassium carbonate. These with water form a 
solution that will stand zero temperatures, but 
are not available where lower temperatures are 
common. 



Non-Freezing Mixtures for Radiators. In 
cold weather, the circulating water, the oil, 
and the carbureter require special attention. 
If the car is to be run regularly during 























The Automobile Handbook 


241 


the winter, it is advisable to use a non- 
freezing mixture in the water-jacket. If the 
car is not to be used regularly, it may not 
be necessary to employ such a mixture, but in 
that case great care is necessary to prevent the 
water from freezing unexpectedly. If the car 
is kept in a barn, the water should be drawn 
off completely after the car has been used, and 
the drainage cock should be so located and the 
piping so arranged that there are no water 
pockets in which the water may freeze and ob¬ 
struct the circulation. If the water freezes in 
the pump, the latter is likely to be broken when 
the car is started the next morning. If water 
freezes in the water-jackets, it will burst the 
jackets unless they are made of copper. When 
the car is left standing for an hour or so, cloths 


Proportions of Glycerine, Alcohol and 
Water. 


Freezing 

Point 

Glycerine and 

Alcohol (equal parts) 

Water 

28° above 

15% 

85% 

15° above 

20% 

80% 

10° above 

24% 

76% 

5° above 

28% 

72% 

Zero 

30% 

70% 

5° below 

33% 

67% 

10® below 

36% 

64% 



242 


The Automobile Handbook 


or lap robes may be thrown over the radiator 
to check the cooling; this is cheaper and safer 
than leaving the motor running. 

The two substances most used to prevent 
freezing are glycerine and calcium chloride. A 
30-per-cent solution of glycerine in water 
freezes at 21° F.; and a solution of one part of 
glycerine to two parts of water is safe from 
freezing at 10° or 15° F.; 40-per-cent solution 
freezes at zero. A small amount of slaked lime 
should be added to neutralize any acidity in the 
solution. Glycerine has the objection that it 
destroys rubber, and the solution fouls rather 
quickly. 

A cheaper mixture, and one preferable where 
the temperatures encountered are likely to be 
below 15° or 20° F., is a solution of calcium 
chloride. This must be carefully distinguished 
from chloride of lime (bleaching powder), 
which is injurious to metal surfaces. Calcium 
chloride costs about 8 cents a pound in bulk, 
and does not materially affect metals except 
zinc. A saturated solution is first made by add¬ 
ing about 15 pounds of the chloride to 1 gallon 
of water, making a total of about 2 gallons. 
Some undissolved crystals should remain at 
the bottom as evidence that the solution is sat¬ 
urated. To this solution is added from 2 to .3 
gallons of water, the former making what is 
called a 50-per-cent, solution. A little lime is 
added to neutralize acidity. A 50-per-cent so¬ 
lution freezes at —15 Q F. 


The Automobile Handbook 


243 


Whether glycerine or calcium chloride is 
used, loss by evaporation should be made up by 
adding pure water, and loss through leakage by 
adding fresh solution. In using the chloride, 
it is important, to prevent the solution from ap¬ 
proaching the point of saturation, as the chlo¬ 
ride will then crystallize out and clog the radi¬ 
ator, besides boiling, and failing to cool the 
motor. A 50-per-cent, solution has a specific 
gravity of 1.21, and should be tested occasion¬ 
ally by means of a storage-battery hydrometer. 
Equally important is it to prevent the 'water 
from approaching the boiling point, whatever 
the density, as boiling liberates free hydrochlo¬ 
ric acid, which at once attacks the metal of the 
radiator and cylinders. 

A solution of two parts of glycerine, one part 
of water, and one part of w'ood alcohol has been 
recommended, which is said to withstand about 
zero temperature. 

Certain mineral oils used for the lubrication 
of refrigerating machinery are recommended 
for cooling, because they remain liquid at very 
low temperatures. They are not particularly 
good heat conductors, however, and will not 
keep the motor as cool as the'water solution. 
If the oil is used, it must be cleaned from the 
radiator by the use of kerosene and oil soap, 
before water can again be used effectively. 

As regards lubrication, the principal danger 
is that the oil will thicken from the cold so that 
it will refuse to feed. This is avoided by using 


244 


The Automobile Handbook 


cold test oil, which remains liquid at lower tem¬ 
peratures than ordinary oil, or by adding to the 
ordinary oil some kerosene or gasoline, and in¬ 
creasing the feed. If the oil tank is located 
close to the engine, it will remain liquid, even in 
quite cold weather. But unless the car has been 
kept in a warm place over night, the bearings are 
liable to run dry before the car has warmed up. 

Cooling Solutions—For Winter. Radiators 
are costly, delicate and composite in construc¬ 
tion, the latter due to the plurality of metals in 
their make-up, hence electrolytic action takes 
place, due to the difference of potential nat¬ 
ural to the different metals immersed in a saline 
bath. Therefore great care should be exer¬ 
cised in the preparation of anti-freezing solu¬ 
tions made up of calcium chloride (common 
salt and water). Any approach to the satura¬ 
tion limit is attended with danger of precipita¬ 
tion. The saturated solution is ascertained at 
60 degrees F., and increasing the temperature 
increases the capacity of the water to hold the 
salts in suspension. 

On the other hand, the Ohmic resistance of 
a solution is lowest at about half saturation. 
To sum up, it is experience that counts, and 
it is still a question as to the extent to which 
saline solutions can be used with safety. Of 
course there is no solution as good as water 
alone, but unfortunately water will expand 
when it freezes, and it will freeze on small prov¬ 
ocation in a radiator. Oil as a cooling medium 


The Automobile Handbook 245 

has points in its favor which some authorities 
claim render it more efficient than water, as 
for instance it has a higher boiling point, about 
double that of water, and as a result the oil 
will not waste away except by leakage. The 
heat exchange occurs at a higher temperature, 
thereby increasing the efficiency of the motor. 
Then also the area of radiating surface may be 
smaller, with a conesquent decrease in weight, 
while the work of the fan is rendered of less 
importance. A light, thin, pure mineral oil is 
the most reliable. Animal, and vegetable oils 
are more apt to become rancid, the acid in them 
also attacks the metal of the radiator. 

Deposits in Water Jacket. If the cooling 
water contains lime or alkali, the heating of the 
water in the jacket will cause these solid sub¬ 
stances to be deposited in the cooling spaces. 
This will soon choke any narrow ports and pre¬ 
vent proper circulation, resulting in overheat¬ 
ing, rapid wearing of the valves, and loss of 
power and efficiency. A simple remedy consists 
of the application, at regular intervals, of a di¬ 
lute solution of hydrochloric, or muriatic, acid, 
made as follows: Dilute one part of muriatic 
acid with nineteen parts of water, and, after 
draining the jacket completely, pour in enough 
of the solution to fill the entire cooling space. 
Allow the mixture to remain in the jacket for 
not more than 8 to 12 hours, after which wash 
the cooling space thoroughly by running clear 
water through it. If the solution is permitted 


246 The Automobile Handbook 

to remain in the jacket longer than the period 
stated, there is danger that the metal may be 
damaged by the action of the acid. The acid 
will soften and dissolve the lime or alkali, and 
the clean water will remove it from the jacket. 
It is generally sufficient to apply this method 
of removing the deposits once every two weeks. 
If neglected too long, the acid will not dissolve 
the deposit. 



tortion of the frame or running gear of an 
automobile, due to unequal spring deflection 
and irregularities of the road surface, means 
should be provided to insure flexible joints or 
connections between the various rotating parts 
of the mechanism of a car. The device shown 
in Figure 114 is not susceptible to any great 
















































The Automobile Handbook 247 

amount of angular distortion, but will transmit 
power with a practically uniform velocity, with 
the axes of the shafts considerably out of align¬ 
ment in vertical or horizontal parallel planes. 

Differential Gears. So long as an automo¬ 
bile moves in a perfectly straight path, its two 
driving wheels turn at equal speed, since they 
must cover equal distances in equal periods of 
time, and it would be perfectly allowable that 
the two wheels should be locked together, as 
there would be no relative motion between 
them. The power could be transmitted to- 
either one, or to both of them with perfectly 
satisfactory results under these circumstances. 
When, however, a ear is to be moved in a curved 
path, as in turning a corner, the driving wheels 
must move at different speeds, since the out¬ 
side one has to cover a longer distance in the 
same time than does J;he wheel which is on the 
inside of the curve. If the two wheels were 
locked together under these conditions, one or 
both of them would be forced to slip, as the 
speeds transmitted to them would be equal, 
while the distances they are to travel are un¬ 
equal. This difficulty is successfully overcome 
by the use of the differential gear which trans¬ 
mits the power from the change-speed gear to 
the rear axle, or driving wheels of the car. 
Differential gears consist of a set of four or 
more gears attached to the ends of two shafts 
that meet, and are usually in line, so that 
both are rotated in the same direction. But, if 


248 


The Automobile Handbook 


either meets with extra resistance it may rotate 
more slowly than the other, or may stop alto¬ 
gether. 

These gears are used on the driving axles 
of automobiles. The axle is made in two parts, 
with a gear on the end of each, where the parts 
come together. Other gears mesh with both 
these axle gears, and are driven from the engine 
by a sprocket and chain, or by bevel gears and 
shaft. These gears turn the axle, but permit 



Fig. 115 


Bevel Gear Differential With Bevel Driving Gear 
and Pinion 

its two parts to turn in respect to each other 
so as to allow the automobile to go around a 
corner without causing the wheels to slide, or 
skid. The rear wheels are each fixed to a half 
of the rear axle, and both receive power, 
hence it is necessary to allow one wheel to turn 
at a different speed from the other, and this 
is accomplished vy means of the differential 
gear. 



















The Automobile Handbook 


249 


Bevel Gear Differential. Fig. 117 shows a 
bevel gear differential in which A and B ar6 the 
two halves of the rear axle, which is divided at 
its center. One of the driving wheels is carried 
on A, and the other one on B, while the inner 
ends of the two half axles are each fitted with 
bevel gear wheels C and D. Meshing with 
these two bevel gears are two, three or four 
bevel gears, two of which are shown at E and 
F. These pinions are supported on radial studs 
which project inwardly from the casing. Upon 
this casing are sprocket or bevel gear teeth 
which are driven from the engine. The teeth of 
each pinion, E and F are at all times in mesh 
with the teeth of both the bevel gears C and D 
on the axle. When the car is in operation, the 
chain or bevel drive revolves the case contain¬ 
ing the pinions, and the power is transmitted 
through the teeth of the pinions E and F to the 
teeth of the gears C and D and thence to the 
axle and wheels. So long as the vehicle travels 
in a straight line, the pinions act as stationary 
driving members, and have no occasion to re¬ 
volve, as the two halves of the axle and their 
gears are moving at equal speeds. They merely 
revolve with the frame. The same teeth of the 
bevel pinions and gears are in contact so long 
as a straight path is traversed. When, however, 
the car is steered in a curve and different veloc¬ 
ities are required in the drivers and the bevel 
gears with which they are connected, the pin- 


250 


The Automobile Handbook 


ions no longer act as fixed driving members, 
but each turns upon its stud and allows the 
necessary relative motion between the two bevel 
gears, and at the same time they continually 
transmit power to the two ends of the axle be¬ 
cause they are always in mesh with each other. 
This compensating action may continue indefi¬ 
nitely through- any amount of variation be¬ 
tween the driving wheel rotation, because one 



Fig. 116 

Bevel Gear Differential Connected to Sprocket 


tooth of the pinions comes into play as fast as 
the preceding one disengages with the bevel 
wheels on the shaft. Fig. 116 presents a larger 
view of the bevel gear differential, the two 
gears on the rear axle being shown as secured 
to the shaft, and to a sleeve on'the shaft. The 
differential employed here has three bevel pin¬ 
ions turning on radial studs, which are secured 
to the arms of a spider at their inner end. A 
differential bevel gear, although most extern 











The Automobile Handbook 


251 


sively used, is open to the objection that the 
bevel gears impose an end thrust upon the two 
halves of the mainshaft on rear axle. This has 
led to the design of differentials in which only 
spur gears are used. 



Fig. 117. 

Bevel Gear Differential. 

Bevel Gear Differential. Fig. 118 show& 
a semi-sectional view of the bevel differential 
gear. The engine shaft carries a bevel gear 
wheel shown in section at a. This gear meshes 
with the large bevel gear b, on the differential 
gear case c. On the inside of this gear case 
are carried a number of small bevel gears, one 
of which is shown in section at d. These are 
free to turn on the studs that hold them to the 
gear case. These gears in turn mesh with bevel 
gears e and f, on the ends of the half axles. 

The principle governing the action of the 
bevel gear differential is similar to that of the 









252 


The Automobile Handbook 


spur gear differential. When the two bevel 
gears e and f on the half axles meet with the- 
same resistance, the small bevel gears d do not 
turn on their bearings; but when the movement 
of one of the gears e or f is resisted more than 



that of the other it lags behind, causing the 
small bevel gears d to turn on their axles suffi¬ 
ciently to equalize the resistance. 

Spur Gear Differential. In the spur dif¬ 
ferential, bevel gears are replaced by gears of 






























The Automobile Handbook 


253 


the spur type, as shown in Fig. 119, a large 
spur gear being secured to each half axle, as 
shown at A and B, exactly as are the bevel 
gears. A double set of spur pinions, E and F, 
having their bearings in the frame, revolve 



upon axes parallel with the axle. For each 
bevel pinion is substituted a pair of spur gears, 
E and F, which mesh with each other, and at 
the same time each one of them is in mesh with 
one of the large gears. The combination of the 































254 


The Automobile Handbook 


motion of each pinion of the pair upon its gear, 
and the motion of the pair upon each other 
produces the same effect as the use of a bevel 
pinion. When the vehicle is rounding a curve, 
one rear wheel moves less rapidly, causing the 
pinions with which it is geared to revolve upon 
their bearings, and thus compensate for the in¬ 
creased resistance. 



Fig. 120 

Sectioned and Side View of Bevel Gear Differential 


Testing Differential Gears. The differen¬ 
tial gear should be tested with a view to locat¬ 
ing any wear or side play. This may be done 
by jacking up the rear axle and shaking one 











The Automobile Handbook 


255 


wheel forward and backward while the other 
is held stationary, and noting how far the 
wheel must be turned before the movement is 
taken up by the flywheel of the engine. Any 
noticeable play will generally be found either 
in the center pinions of studs of the differential 
gear, in the large and small bevel gears, in the 
clutch sleeve, or in the universal joints. The 
differential gear, and live axle of modern cars 
seldom give trouble if kept properly lubricated, 
and the car’s mileage should run up into many 
thousands before any considerable amount of 
play is evident. The joint pins of the propeller 
shaft may become loose through wear, in which 
case a knocking noise in the transmission gear 
will indicate the cause and locatdon of the 
trouble. These pins may be readily replaced 
with new ones at small cost. If the play is 
found in the bevel gears, the small gear should 
be adjusted to mesh deeper with its larger mate. 
This may be done by means of the adjustable 
locking ring or by inserting a washer of the 
proper thickness. It may be found, however, 
that no adjustment is necessary, and a thor¬ 
ough cleaning with gasoline to remove all oil 
and grease will be all that is required. The 
case should then be refilled with the quantity 
of oil and grease recommended by the manu¬ 
facturers. 


256 


The Automobile Handbook 


Driving, Automobile. When on the open 

road, away from cities or towns, the fol¬ 
lowing rules should be borne in mind. (1) 
Drive with moderate speed on the level, slow 
speed down hill, and wide open throttle for 
hill climbing, or getting up speed only. (2) 
The condition of the road should be noticed, 
the presence of mud or dust thereon furnishing 
sufficient reason for slowing down somewhat 
for the sake of other road users. (3) The or¬ 
dinary rules of the road regarding the negotia¬ 
tion of turns, and crossings, also' the overtak¬ 
ing or passing of other vehicles should be ad¬ 
hered to, even though a low^er rate of speed is 
involved thereby. (4) A sharp lookout should 
always be kept for traffic of all kinds, as well 
as on approaching schools, churches, or public 
buildings, and also for road signs indicating 
danger, caution, etc. (5) When on the road 
the autoist should show courtesy to other road 
users. Courtesy in autoists is much appreci¬ 
ated, and goes a long way toward removing 
the prejudice which exists in many places* 
against automobiles. 

In passing another vehicle going in the same 
direction, turn out at least 75 feet back of it so 
that j r ou have a clear view of the road ahead. 
If another vehicle is coming toward you and 
near at hand, do not try to pass. 

When preparing to turn or stop always signal 
to drivers behind with your hand and avoid 
stopping suddenly. 


The Automobile Handbook 


257 


Gear—Changing. In changing gears the au- 
toist should endeavor to have the motor and 
car moving at nearly corresponding rates of 
speed before the clutch is engaged. With the 
planetary type of gear, changing is simple, and 
drivers usually guess at the proper period at 
which to make the change, any mistake in esti¬ 
mating the rates of the ear and motor being of 
little consequence, as the bands will slip instead 
of transmitting the shock .to the gear. A simi¬ 
lar action occurs in the case of individual 
clutch or friction gears, but with the sliding 
type severe strains and shocks have to be taken 
up by the clutch, and are usually transmitted in 
part to the gear if the clutch is not slipped. 
What applies to the sliding type in general ap¬ 
plies to the other types as well. 

In changing from a lower to a higher gear it 
will be necessary to speed up the motor by 
means of the throttle or accelerator in order to 
store enough energy in the flywheel to furnish 
the work needed to accelerate the car to its 
new speed. As the speed of the car increases 
the higher gear should be engaged, the autoist 
not being in too great a hurry to make the 
change. The movement of the change gear le¬ 
ver should be made quickly in order that the 
car does not los^ way. When changing.from a 
higher to a lower gear the change should be 
made as quickly as possible before the car has 
time to slow down. When climbing a steep hill 
it should be ascended as far as possible on the 


258 The Automobile Handbook 

high gear by proper use of the throttle and 
spark, and the change down to the lower gear 
made as soon as the motor begins to labor or is 
in danger of stopping. The presence of an 
unusual number of passengers in the car will 
affect its ability to negotiate grades which ordi¬ 
narily are taken on the high gear, and the auto- 
ist should remember this and not attempt to 
force the car to travel on that gear with the in¬ 
creased load, but resort to a lower gear. 

Reversing—Backing Up. Among other things 
connected with driving which is apt to be neg¬ 
lected, is reversing, or driving a car backward. 
Usually a car is never reversed for more than 
a few yards at a time and the maneuvering in¬ 
volved requires no great skill. Steering a car 
when running backwards is diametrically op¬ 
posite to that when running forward. A turn 
of the wheel to the left steers the car in the 
opposite direction to the right, and vice versa. 
The usual mistake made in reversing is in turn¬ 
ing the steering wheel too far, and describing 
zigzags in the road as a result. The autoist 
should remember that the reverse gear of a 
sliding change gear should never be engaged 
until the car has been brought to a full stop. 

Brakes, Proper Use of. Next to the motive 
power in importance come the brakes. There 
are a number of points regarding brakes that 
every autoist should know and remember. First 
and most important is the fact that brakes vary 
in their effectiveness, and that freedom from dis- 


The Automobile Handbook 


259 


Aster depends upon the brakes being kept in 
good condition and properly adjusted. Second, 
while a brake may be perfectly satisfactory for 
slowing down, it by no means follows that it will 
bring a car to a stop as it should, nor hold the 
viar from going backward. Third, brakes 
ohould be tested frequently with the car in 
motion, the pedal or hand lever being applied 
until the car slows down, or stops. The distance 
covered in making this test should be noted, 
and a greater distance allowed in making stops 
on the road. 

In applying brakes, the application should be 
gradual, reducing the speed of the car as quickly 
as possible without locking the wheels. As long 
as the tires retain their grip on the road, the 
powerful retarding action of the brake contin¬ 
ues, but when the wheels are locked the brakes 
have little or no effect, and the car will either 
slide along, or skid, in either case being be¬ 
yond the control of the driver. Should the 
wheels become locked while descending a hill, 
the brakes should be released until the wheels 
are again revolving, and then reapplied gradu¬ 
ally, until they act satisfactorily. 

Brakes should be examined at regular in¬ 
tervals in order to ascertain if the lining is in 
good condition. If worn, the old lining should 
be replaced with new. If the brakes are of the 
internal-expanding type, the shoes may have 
become worn, in which case they should be re¬ 
newed. Toggle joints and adjusting nuts 


260 The Automobile Handbook 

should be inspected, and any looseness taken up. 
Brakes should be adjusted on *be road, as any 
improper adjustment of the equaliser bar will 
have a strong tendency to make the car skid. 
Both brakes should be adjusted alike, that the 
braking force applied by the equalizer may be 
transmitted to the wheels equally. 

Side Slip, or Skidding. If the rate of rota¬ 
tion of a wheel is greater than the rate of ad¬ 
vance over the road, the wheel loses adhesion 
and thereafter it is just as easy for it to move 
in one direction as in another. 

The wheel can now slip sideways as easily 
as it can slip forwards, particularly when it has 
the rounded section slightly flattened, which is 
the case with pneumatic tires. When traveling 
straight ahead, and with the motor out of gear, 
skidding does not usually occur. A slight turn 
given to the steering wheel checks the speed 
and introduces a side pressure on both front 
and rear wheels, due to the machine tending to 
continue its path in a straight line. Generally 
this side pressure will not cause skidding. If, 
however, the motor be suddenly thrown in gear, 
or the brakes suddenly applied, or, what 
amounts to the same, a large turn is given the 
steering wheel, the wheels find themselves 
either rotating more than in proportion to their 
advance, or advancing more than in proportion 
to their rotation. This immediately causes a loss 
of adhesion, which, once established, causes the 
car to skid or side-slip. 


The Automobile Handbook 


261 


Spark—Regulation of. Upon the proper use 
of the sparking device depends the economy oi 
the motor, and in many cases the safety of the 
driver. On some cars the sparking point on the 
magneto is fixed, and the autokt controls the 
ear by the throttle only. There are a number 
of cars in use which employ the battery in con¬ 
nection with separate coils or a single spark sys¬ 
tem, or a magneto on which the spark can be 
regulated by the driver. When starting, the 
spark should be retarded in the case of battery 
ignition, to prevent backfiring, and slightly ad¬ 
vanced to a certain point, depending on the 
motor and magneto, in the case of magneto igni¬ 
tion. When it is desired to slow the motor 
down below the point obtained by throttling 
only, the sp#rk is likewise retarded. In ordi¬ 
nary running, a position of the spark lever can 
be found which will give fair average results 
through a considerable range of speed without 
changing its position, and this position varies 
with each motor, and can be found by experi¬ 
ence. When a higher rate of speed is desired, 
the throttle is opened and the spark advanced 
gradually. If a grade is to be negotiated it 
should be “rushed” if possible, the throttle be¬ 
ing opened full and the spark well advanced 
until the motor begins to slow down and 
“knock,” when the spark should be retarded to 
correct this. The autoist should always keep 
the spark as far advanced as possible, without 
causing the motor to knock. 


262 


The Automobile Handbook 


"When to Retard the Ignition. Always 
retard the ignition before starting the motor, 
and take great care that the ignition is retarded 
and^not by mistake advanced. Some cars are 
fitted with a device which prevents the starting 
crank being turned unless the spark is retarded. 
If it is not clear as to which way to move the 
ignition lever to retard the ignition, move the 
commutator in the same direction as the cam¬ 
shaft rotates. 

As soon as the motor slows a little when go¬ 
ing uphill, retarding the spark enables more 
power to be obtained from the motor at the 
slow speed, that is to say, if the spark is not 
retarded the motor will go slower than if it is 
retarded. Do not retard the lever to the utmost 
under these conditions; on the contrary, retard 
the lever to such a point that the knocking (due 
to the wrong position) ceases. 

Retarding the spark causes the maximum 
pressure of the explosion to occur at the best 
part of the stroke, or, rather, the mean pressure 
of the explosion stroke will be lower if the best 
point of ignition by retarding is.not found. This 
is a matter of some skill and practice. 

To slow the motor, cut off as much mixture 
as the throttle allows, then slow the motor still 
further by retarding the spark, but on no ac¬ 
count retard the spark when the throttle is full 
open (for the purpose of slowing the motor), 
as the motor will merely discharge a quantity 
of flame at a white heat over the stem of the 


The Automobile Handbook 


263 


exhaust valve, burning it, softening it, and 
making it scale. 

When to Advance the Ignition. With too 
early ignition the pressure upoi\ the piston be¬ 
comes excessive and without any adequate re¬ 
turn of useful work or energy. If the ignition 
he retarded too much, the maximum explosive 
pressure occurs too late during the working 
or power stroke of the piston, and^tlie combus¬ 
tion of the gases is not complete when the ex¬ 
haust-valve opens. Greater motor speed re¬ 
quires an early ignition of the charge, but 
greater .power calls for late or retarded igni¬ 
tion. 

The reason for advancing the spark when 
fast running is required, is that the explosion 
or ignition of the charge is not instantaneous 
as may be supposed, but requires a brief inter¬ 
val of time for its completion. 

It may be well to explain without entering 
into theoretical details, that when a motor is 
running at normal speed, the ignition-device is 
so set that ignition takes place before the pis¬ 
ton reaches the end of its stroke. The later 
the ignition takes place the slower the speed 
of the motor and consequently the less power it 
will develop. If, however, in starting the mo¬ 
tor the ignition-device were set to operate be¬ 
fore the piston reached the end of its stroke, 
hackfiring would occur, resulting in a reversal 
of the operation of the motor and possibly in 
injury to the operator. 


264 


The Automobile Handbook 


Car Inspection. Most autoists are content to 
make all their inspection of the car and its mech¬ 
anism from above, and rarely give more than a 
casual glance 'below the frame except when, 
trouble occurs. On cars fitted with pressure-feed 
on the gasoline, the piping should be frequently 
inspected, on account of the danger from fuel 
leakage. Such inspections should be made 
when the mo+or is stopped, and the pressure still 
turned on. The tank should be gone over for 
leaks arising through the opening of its seams 
from vibration, or the loosening of the union 
connecting the fuel lead with the tank. The 
lead and its connection to the carbureter should 
also be examined for leaks and abrasions due to 
rubbing against other parts of the mechanism. 
If any such are found they should be immedi- 
diately repaired. Twine, tire tape, or rubber 
bands will act satisfactorily as fenders to pre¬ 
vent further mischief. Unions which cannot be 
made tight by screwing up should be taken 
apart and the male connections coated with 
soap or red lead, which will render them tight 
for a considerable time. 

After going over the fuel system, the brake 
rods and steering connections should be exam¬ 
ined for loose joints and broken oil and grease 
cups. Grease boots on the drive-shaft joints 
should be seen to be sound, and filled with 
grease. A cleaning out of the dirt from the in¬ 
terior of the mud-pan will often reveal lost cot¬ 
ter pins or nuts, and tend to a more agreeable 
handling of the draincocks, carbureter and fil- 


The Automobile Handbook 


265 


ter. This time .will be well spent when the 
chances of fire or accidents arising from faulty 
steering or brake connections are taken into 
account. 

Dont’s. In the first place don’t forget to as¬ 
certain the fact that the ignition mechanism is 
retarded before cranking the motor. Many a 
sprained wrist and a few cases, of broken 
heads or arms have been caused by the neglect 
of this simple precaution. It is a good plan to 
have the ignition-control spring so actuated that 
in its normal position it is always retarded. 

Don’t use the electric starting motor to pro¬ 
pel the car. It ruins the battery. 

Don’t use a match or a small torch to inspect 
the carburetor. It sometimes leads to unex¬ 
pected results. 

Don’t forget to fill the gasoline tank before 
starting. 

Don’t smoke while filling the gasoline tank. 

Don’t take out all the spark plugs when 
there is nothing the matter, except that there 
is no gasoline in the tank. 

Don’t forget to always have an extra spark 
plug on the car. 

Don’t allow the motor to race or run fast 
when out of gear. If the car is to be stopped 
for a few minutes, without stopping the motor, 
retard the ignition and also throttle the charge, 
so that the motor will run as slowly as possible. 

Don’t fill the gasoline tank too full, leave an 


The Automobile Handbook 


io6 


air space at the top or the gasoline will not flow 
readily. 

Don’t put grease in the crank case of the 
motor, it will clog up the oil holes and prevent 
the oil from circulating. 

Don’t fill the gasoline tank by lamp or candle 
light, something unexpected may happen. 

Don’t keep on running when an unusual noise 
is heard about the car, stop and find out what 
it is. 

Don’t start or stop too suddenly, something 
may break. 

Don’t pour gasoline over the hands and then 
rub them together. That rubs the dirt into the 
skin. The proper way to do is to saturate a 
towel with gasoline and then wipe the dirt off. 

Don’t forget to examine the steering gear 
frequently. 

Don’t fail to examine the pipe between the 
carbureter and the admission-valve occasionally. 
The pipe connections sometimes get loose and 
allow air to enter and weaken the mixture. 

Don’t forget to see that there is plenty of 
water and gasoline in the tanks. 

Don’t fail to clean the motor and all the 
wearing parts of the car occasionally. 

Don’t forget to oil every part of the motor 
where there is any friction, except the valve 
stems. 

Don’t forget to put distilled water in the bat¬ 
tery every ten to fifteen days. 


The Automobile Handbook 267 

Dynamometer. A dynamometer is a form of 
equalizing gear which, is attached between a 
source of power and a piece of machinery when 
it is desired to ascertain the power necessary to 
operate the machinery with a given rate of speed. 

Electricity, Forms of. Electricity or electri¬ 
cal energy may be generated in several ways— 
mechanically, chemically and statically or by 
friction. By whatever means it is produced, 
there are many properties which are common 
to all. There are also distinctive properties. 
The current supplied by the storage battery 
will flow continuously until the battery is prac¬ 
tically exhausted, while the current from a dry 
battery can only be used intermittently; that is, 
it must have slight periods of rest. 

The dynamo or magneto current is primarily 
of an alternating nature, or one which reverses 
its direction of flow rapidly. In use, this alter¬ 
nating current is changed into a direct or con¬ 
tinuous current flowing in one direction only, 
by means of a commutator. Any of the forms 
described are capable of igniting an explosive 
charge in a motor cylinder, but the static or 
frictional form of electricity is not used for this 
purpose on account of its erratic nature. 

Electromotive Force, Definition of. The 
cause of a manifestation of energy is force; if 
it be electric energy in current form it is called 
electromotive force. An electromotive force 
or pressure of one volt will force one ampere 
through one ohm of resistance. 


268 


The Automobile Handbook 


Engines, Internal Combustion. 

Engine—Construction of. An automobile 
engine 'should answer the following require¬ 
ments in order to meet the demands of the mo¬ 
tor user: It must be of light weight in propor* 
tion to its horse power, so that as large a pro¬ 
portion of its power as possible may be avail¬ 
able for propelling the useful load, and but lit¬ 
tle demanded to move its own weight; it must 
be compact, in order that it shall not occupy 
too large a proportion of the available room of 
the car; it must operate without undue noise 
and vibration; it must be fully enclosed as a 
protection against the weather, and still it must 
be so located as to be easily accessible fo* in¬ 
spection, oiling and repairs; its operation n^atst 
be automatic for considerable periods of time, 
as regards cooling and lubrication; it must be 
capable of running very slowly, or very fast at 
will, and of developing little, or much power: it 
must be supported upon the car in such a man¬ 
ner that its power may be most readily and 
efficiently transmitted to the driving wheels, 
and it must further be carried upon springs so 
that the jar and shock from the road shall not 
be transmitted to it. 

Explosive Motors. Explosive motors are of 
three forms, known as stationary, marine and 
automobile. Their general characteristics are 


The Automobile Handbook 


269 


implied by their various designations. The sta¬ 
tionary motor may be either vertical or hori¬ 
zontal. Marine motors, designed for applica¬ 
tion to boats, are almost invariably vertical. 
Automobile motors are of comparatively receni 
introduction and of great variety, the aim of 
the designers being to secure the maximum of 
power and minimum of weight. They also 
may be vertical or horizontal. 

These three forms may be again divided into 
two-cycle and four-cycle types. In the former 
an explosion occurs at every revolution. In the 
latter there is an explosion at every alternate 
revolution. 

Explosive motors are dependent for success¬ 
ful operation on two things: First, a charge of 
gas or vapor, mixed with sufficient air to pro¬ 
duce an explosive mixture, and second, a 
method of firing the charge after it has been 
taken into the combustion chamber of the 
motor. 

When coal gas is used the supply is taken 
from the main and mixed directly with the nec¬ 
essary proportion of air. When gasoline is 
used, air is mixed with it in the correct pro¬ 
portion by carbureting devices. 

After the charge of gas and air has been 
taken into the cylinder it is compressed, as will 
be shown later, by the action of the motor itself 
and then fired, usually by an electric spark 
actuated by the motor, but sometimes by the 
use of a tube screwed into the cylinder and 


270 


The Automobile Handbook 

i 




































































































The Automobile Handbook 


271 


Interl il Combustion Automobile Engine. 1, Oil 
Val e Lever. 2, Oil Valve Adjustment. 3, Oil 
Val e Lifter. 4, Oil Valve Slot. 5, Oil Tank 
Co^ >r. 6, Water Jacket. 7, Oil Tank. 8, Oil 
Val e Spring. 9, Oil Valve Plunger. 10, Oil. 11, 
Oil &auge Glass. 12, Oil Valve. 13, Oil Feed 
WiJ low. 14, Water Inlet. 15, Cylinder Joint. 
16, Cylinder Wall. 17, Crank Case Breather. 

18) Oil Feed Pipe. 19, Connecting Rod Bear- 
inf > 20, Crank Pin. 21, Rod Bearing Bolt. 

22. Oil Scoop. 23, Crank Shaft Timing Gear. 
24, Crank Case. 25, Oil Lever Overflow. 26, 
Oankcase Oil. 27, Oil Drain Cock. 28, Cam 
Shaft Timing Gear. 29, Cam Shaft Plate. 30, 
Cam Shaft. 31, Cam Shaft Housing. 32, Ex¬ 
haust Outlet. 33, Gasoline Pipe to Carburetor. 
34, Carburetor Priming Lever. 35, Carburetor. 
36, Throttle Lever Rod. 3 7, Gasoline Adjust¬ 
ment. 38, Valve Lifter Rod. 39, Valve Stem 
Adjustment. 40, Fibre in Valve Plunger. 41, 
Cylinder Space. 42, Valve Spring. 43, Ex¬ 
haust Pipe. 44, Connecting Rod. 45, Piston. 
46, Wrist Pin Set Screw. 47, Oil Groove in 
Piston. 48, Wrist Pin. 49, Exhaust Manifold. 
50, Manifold Clamp Nut. 51, Intake Manifold. 
52, Intake Passage in Cylinder. 53, Valve Stem. 
54, Valve Head. 55, Valve Opening, Seat and 
Face. 56, Piston Rings. 57, Combustion Space. 
58, Valve Pocket. 59, Priming Cup. 60, Valve 
Cap. 61, Water Outlet Header. 63, Valve Cap. 


272 


The Automobile Handbook 




♦ 


\ 




Fig. 122 

Front and Side View of Section Through Four Cylinder Automobile Engine 




















































































The Automobile Handbook 


273 


heated from the outside, the heat, of course, 
being communicated to the gas. The resulting 
explosion operates the motor. 

The principal parts of a four-cycle explosive 
motor are the cylinder, the piston, the piston 
rings which fit into grooves in the piston: two 
sets of valves, one to admit the charge and the 
other to permit it to escape after the explosion; 
a crank shaft and connecting rod which con¬ 
nect it with the piston head, and a flywheel, 
w T hose presence insures steady running of the 
motor, and whose further functions will be 
better understood as the description proceeds. 
In the two-cycle form of motor there is really 
but one valve, the exhaust and admission-ports 
being covered and uncovered by the piston it¬ 
self. 

All of the parts referred to are of the motor 
proper. Other parts, which are separate from 
the motor but on which its operation depends, 
are the carbureter, which supplies the charge 
of gasoline vapor and air for a gasoline motor, 
or a mixing chamber for mixing air and gas in 
the case of a gas motor, and the batteries and 
other parts of the electrical ignition device. 

A part which has no connection with the 
actual running of the motor but with which 
practically all are fitted is the muffler, whose 
purpose is to deaden the sound *of the explo¬ 
sion. 

The cylinders of all except very small motors 
are as a rule partly encased in a chamber 


274 


The Automobile Handbook 


through which water is circulated, the object 
of this being to keep the cylinder cool. 

In other cases a current of cool air is sent 
around each of the cylinders by means of ducts 
and one or more fans, this air acting as a direct 
cooling agent. 



Fig. 123 

Section Through Six Cylinder Long Stroke Engine 


Pistons. The piston used in a gasoline motor 
cylinder is of the single-acting or trunk type. 
It is made of an iron casting which is a good 
working fit in the cylinder. Around the upper 
























Tive Automobile Handbook 


275 


end of the piston three or four grooves are cut, 
and in these grooves the piston-rings fit. The 
rings are made of cast iron, and the bore of the 
ring being eccentric to its outer diameter, there 
is a certain amount of spring in them, and so 
pressure is caused against the cylinder wall, 
preventing any of the expanding gases passing 
the piston. 

Piston Materials. Until recently it has been 
the universal practice to make internal combus¬ 
tion engine pistons of cast iron for the reason 
that this material does not warp under heat to 
such an extent as does steel. The principal 
objection to cast iron has been its comparatively 
high weight, this weight being necessary because 
of the lack of great strength in the metal. It is 
a well known fact that cast iron is very brittle. 
With the advent of the modern high speed en¬ 
gine, experiments were conducted with steel pis¬ 
tons because of the fact that they allowed of 
lighter construction with equal strength. Steel 
pistons have done satisfactory work, but are very 
high in production cost, and this has prevented 
their general introduction. 

The necessity for reducing the Weight of the 
reciprocating parts has more recently led to the 
introduction and use of pistons made from alloys 
of aluminum, which, of course, gives the desired 
reduction in weight. The fit of the piston in the 
cylinder cannot be so tight when cold as with 
cast iron or steel, but as soon as the engine has 
run a few moments, the expansion due to heat 


276 The Automobile Handbook, 

allows the piston to fit close enough for all prac¬ 
tical purposes. These pistons are now fitted in 
many makes and models of stock cars and may 
be fitted to cars already in use. 

Piston Displacement. The piston displace¬ 
ment of a motor is the volume swept out by the 
piston, and is equal to the area of the cylinder 
multiplied by the stroke of the piston. The 
expression, cylinder volume, is sometimes con¬ 
founded with the term piston displacement. 
This is erroneous, as the cylinder volume is 
equal to the piston displacement, plus the com¬ 
bustion space in the cylinder head. 

Pistons, Length of. For vertical cylinder 
motors the length of the piston should not on 
any account be less than its diameter, while a 
length equal to one and one-quarter or even 
one and one-third diameters is better. For mo¬ 
tors with horizontal cylinders the length of the 
piston, in any case, should not be less than one 
and one-third diameters, and if possible one 
and one-half diameters or over. 

Piston Position. There is nothing more con¬ 
fusing to many motorists—not only to the be¬ 
ginner, but to many who are proficient in the 
general care and operation of their motor cars 
—than the relative various positions, in a four¬ 
cycle engine, of the four pistons on any of their 
four cycles of compression, work, explosion, 
and exhaust, this being the order of the cycles. 

In the following illustrations the pistons are 
shown as they are usually placed in relation to 


The Automobile Handbook 


277 





Fig. 



Fig. 125 







































































































































278 


The Automobile Handbook 




Fig 127 























































































































The Automobile Handbook 


279 


one another. That is, pistons 1 and 4 are at 
the top of their strokes when pistons 2 and 3 
are at the bottom, and, obviously, vice versa. 
The figures over the pistons in each diagram 
represent their order of number, counting from 
either end of the engine. 

In Fig. 124, cylinder 1 is ready to descend 
on its intake stroke—having finished its ex¬ 
haust stroke—and cylinder 4 is ready to de¬ 
scend on its working stroke—having finished 
its compression stroke. Cylinders 2 and 3 are 
ready to move on their up strokes, No. 2 on its 
compression, having finished its intake, and 
No. 3 on its exhaust, having finished its working 
stroke. The results "are that the pistons are 
brought into the positions shown in Fig. 125. 
This means that cylinder No. 1, having com¬ 
pleted its intake downward stroke, is ready for 
its compression up stroke; No. 2 has moved up 
on compression and is ready to go down on 
work; No. 3 has finished exhausting and is 
ready for intake and No. 4 has finished the 
work stroke and is ready to move up on ex¬ 
haust. Piston No. 2, having completed its work 
stroke, the pistons are brought back to the po¬ 
sitions shown in Fig. 124, but with an altered 
condition of the cycle represented by each, as 
shown in Fig. 126. The pistons are now ready 
to move to the positions shown in diagram 2, 
with an altered cycle condition. Cylinder No. 
1 moves down on work; No. 2 up on exhaust; 


280 


The Automobile Handbook 


No. 3 up on compression and No. 4 down on in¬ 
take, see Fig. 127. 

When the cycle of each has been completed, 
from the abov£ starting points of No. 1, ex¬ 
haust; No. 2, intake; No. 3, work, and No. 4, 
compression, the pistons are then back not only 
in the position of Fig. 124, but with the same 
condition of cycles. 

This explanation has been in the order of the 
cylinder numbers, but the effect of each cycle 
of each cylinder w T ill be easier traced if it be 
remembered that the order in which the cylin¬ 
ders work is: Cylinder 1, then cylinder 3, then 
cylinder 4, and then cylinder 2, and then repeat 
indefinitely. From this and the above illustra¬ 
tions it will be easily understood that as piston 
No. 1 goes down on its work stroke, No. 3 
comes up on compression stroke, and is then 
ready for the work, which is a down stroke 
bringing No. 4 up on compression. No. 4 then 
goes down on work and brings No. 2 up on com¬ 
pression, then it goes down on work and brings 
No. 1 up on compression for the repeating of 
cycles. This shows that each synchronized pair, 
1-4 and 2-3, always have one cycle between them 
as they move together, either up or down. 

Piston-Rings. To ensure proper compression, 
it is absolutely essential that the piston-rings 
should be kept lubricated; consequently when 
the motor has been idle for some time, the 
compression at the start is often poor. Any fail¬ 
ure in the lubrication while running will, of 


The Automobile Handbook 


281 


course, have the same effect, such, for example, 
as in the case of overheating, or when the sup¬ 
ply is intermittent. Sometimes the piston- 
rings get stuck in their grooves with burnt oil, 
through overheating, and the compression es¬ 
capes past them. Thorough cleaning with kero¬ 
sene, and fresh lubricating oil will settle the 
matter. In motors where the rings are not 
pinned in position, the slots may work round so 
as to coincide. In this case they will have to be 
moved around. Sometimes burnt oil may, ap¬ 
parently, have the opposite effect on piston- 
rings, for by causing the piston to grip in the 
cylinder, it will produce considerable resist¬ 
ance, and the operator might erroneously think 
in consequence that his compression is good. In 
every case, after a long-run, a little kerosene 
should be injected into the cylinders to clean 
the rings. 

Many of the specially prepared carbon remov¬ 
ers will also act to clean the piston rings. 

Flywheels. One of the first and most impor¬ 
tant considerations in connection with the con¬ 
struction of a gasoline automobile motor is the 
proper diameter and weight of the flywheel. If 
the diameter and weight of the flywheel be 
known, the speed of the motor or its degree of 
compression will become a variable quantity. 
On the other hand, if the speed of the motor 
and the degree of compression be fixed, the di¬ 
ameter or weight of the flywheel rim must be 
varied to suit the other conditions. 


282 


The Automobile Handbook 


While it is true that the weight of the flywheel 
may be reduced as the number of cylinders is 
increased, there is a practical limit below which 
it is inadvisable to reduce the weight at the 
rim. Even should the number of cylinders be 
sufficient to cause a balance between the work¬ 
ing strokes, it would still be desirable to add a 
rotating weight to compensate in some measure 
for the several reciprocating masses, such as 
pistons, connecting rods, crankshaft webs, etc. 
Engines have been built for racing purposes 
without flywheels, but they were unsuccessful. 

Camshaft. Fig. 128 is a sectional view of a 
motor cylinder and illustrates the principle and 
action of the camshaft. In many motors one 
camshaft serves to open both intake and exhaust 
valves, while in other motors there is a cam-shaft 
for each set of valves. Besides opening the valves, 
the cams determine the length of time the valves 
remain open, also the speed with which it-opens 
and closes. Referring to Fig. 128, A is the crank¬ 
shaft, P the piston, D is the cam-shaft which 
carries the cam E. The speed of the cam-shaft 
depends upon the type of engine. The one 
shown in Fig. 128 is driven at half the speed of 
the crank-shaft through the gear wheels B and 
C, B being one half the size of C. IT is the 
valve to be opened, which in opening must be 
lifted off its seat. This is done when the cam 
E revolves and raises the roller G on the lower 
end of lifter rod F which extends upward rest¬ 
ing against the lower end of the stem of valve 


The Automobile Handbook 283 

H, although between the two rods, or rather at 
their point of contact are nut and lock-nut L, 



for adjusting the length of F when timing the 
valve. K is a spiral spring, the function of 













2S4 


The Automobile Handbook 


which is to close the valve, after the cam E trav¬ 
els around and allows G to drop. Directly 
above valve H is the intake valve M, which in 
this case opens downward. This valve opens 
automatically, due to the suction of the piston 
in moving downwards on the intake stroke, but 
is kept closed during the compression and ex¬ 
haust strokes of the piston, by the pressure in 
the cylinder. 

Modern forms of construction make the cam¬ 
shaft and cams from one piece of steel, and the 
cams are then said to be integral with the shaft. 
This method makes it possible to place the cams 
in exactly the right position at the factory, and 
the danger of lost power from improper placing 
is thus greatly reduced. 

Manifold, Inlet. The internal diameter of 
the admission or inlet-pipe leading from the 
carbureter to the admission-valve chamber should 
not exceed one-fourth the diameter of the motor 
cylinder. 

This limitation is necessary in order to pro¬ 
duce as great a partial vacuum as is possible in 
the admission-pipe. The carbureter should be 
placed as close as possible to the admission- 
valve chamber of the motor in order to secure 
the best results. Short turns or bends in the 
admission-pipe greatly increase the air-friction 
in the pipe, and at high speeds greatly diminish 
the volume of the charge drawn into the cylin 
der by the inductive or suction action of the 
motor-piston. 


The Automobile Handbook 285 

The desire to prevent condensation of the 
gasoline vapor in the inlet manifold has led 
many designers to fasten the carburetor flange 
directly to the cylinder casting at the point of 
entrance to the inlet valve passages. Others 
have either completely or partially water-jack¬ 
eted the inlet manifold for its entire length. In 
all cases, the distance between the carburetor 
mixing chamber and the inlet valve port is 
made as short as possible. 

A troublesome condition on many cars is 
that caused by minute air leaks in the inlet 
piping and connections. If carburetor adjust¬ 
ment is diffioult, squirt liquid gasoline on the 
inlet connections with the engine running. Any 
change in engine speed is a sure indication that 



Fig. 129 

The radius of curvature of the pipe on its cen¬ 
ter line should not £e less than twice the out- 














286 The Automobile Handbook 

side diameter of the pipe. If space allows, a 
radius of three times the outside diameter of 
th'e pipe will give better results than two diam¬ 
eters. 

Combustion Chamber. That part, of an ex¬ 
plosive motor in which the gases are com¬ 
pressed, and thqn fired, usually by an electric 
spark, is known as the combustion chamber. 
The interior of the combustion chamber should 
be as smooth as possible and kept free from 
soot, or hard carbon deposits such as are in¬ 
duced by excessive lubrication, or the use of too 
rich an explosive mixture. 

It will be found to be no small task in design¬ 
ing an explosive motor with the usual form of 
valve construction and operation, to keep the 
combustion chamber down to the required di¬ 
mensions and at the same time have it free from 
bends or contracted passages between the com¬ 
bustion space and the valve chamber. 

Many attempts have been made to obviate 
this difficulty by making the combustion cham¬ 
ber simply a straight extension, or continuation 
of the cylinder. In this manner both the ad¬ 
mission and exhaust-valves can be placed in the 
cylinder itself and an ideal combustion space 
secured. This plan has, however, certain dis¬ 
advantages, from the fact that it not only 
lengthens the motor, but requires a more com¬ 
plicated form of valve operating mechanism 
than if the valve chamber were at the side of 
the cylinder as is usual. 


The Automobile Handbook 


287 


TABLE 9. 

PROPERTIES OF COMPRESSED AIR 


Comp, in 
Atmos 
pheres. 

•Mean 

Pressure. 

Temp, in 
Degrees 
Fah. 

•Gauge 

Pres¬ 

sure. 

•Absolute 

Pressure. 

•Isother¬ 
mal Pres¬ 
sure. 

1 1 

0 

60 | 

0 

14.7 


1.68 

7.62 

145 | 

10 

24.7 

30.39 

2.02 

10.33 

178 

15 

29.7 

39.34 

2.36 

12.62 

207 | 

20 

34.7 

48.91 

2.70 

14.59 

234 | 

25 

39.7 

59.05 

3.04 

16.34 

252 

30 

44.7 

69.72 

3.38 

17.92 

281 

35 

49.7 

80.87 

3.72 

19.32 

302 

40 

54.7 

92.49 

4.06 

20.57 

324 

45 

59.7 

104.53 

4.40 

21.69 

339 

50 

64.7 

116.99 

4.74 

22.76 

357 

55 

69.7 

129.84 

5.08 

23.78 

375 

60 

74.7 

143.05 

5.42 

24.75 

389 

65 

79.7 

156.64 i 

5.76 

25.67 

405 

70 

84.7 

170.58 

6.10 

26.55 

420 

75 

89.7 

184.83 


♦In pounds per square inch. 


Air Properties of Compressed. Table 9 gives 
the Mean pressure, Temperature in degrees 
Fahr., Gauge pressure, Absolute pressure and 
the Isothermal or heat pressure of air under 
compression of from 1 to 6.10 atmospheres. 

As energy in the form of power must be used 
to compress air to any desired pressure, so is 
energy in the form of latent or stored heat 
given up by the air during the operation of 
compression. This heat consequently increases 
the pressure resulting from the compression, 
but not directly in proportion to the degree of 
compression in atmospheres. 

This increase of pressure above the Adiabatic 
or calculated pressure is known as the Isother¬ 
mal or heat-pressure. As the values of this 












288 


The Automobile Handbook 


pressure cannot be calculated by the use of 
ordinary mathematics, but involve the use of 
logarithms, Table 1 gives these values for each 
degree of compression given. 

Many persons who are not familiar with the 
properties of gases, estimate the pressure re¬ 
sulting from the compression to a given number 
of atmospheres, as the number of atmospheres 
multiplied by the atmospheric pressure, which 



at sea level is taken as 14.7 pounds per square 
inch. 

This assumption is erroneous and will often 
lead to grievous mistakes in motor design, 
generally giving too much compression, which 
results in premature ignition, commonly known 
as backfiring. Such methods of calculation 
would be true if the air, after compression, was 
stored in a reservoir and allowed to cool, but 
under no other conditions. 


















The Automobile Handbook 


289 


Four-Cycle Motor. Fig. 130 furnishes two 
sectional views of a four-cycle type of motor 
with some of the parts removed, as in Fig. 121. 
It shows a cylinder C, admission-valve A, a 
piston P, and exhaust-valve E. 

The left-hand view shows the piston P about 
to suck in a charge of vapor, by the same 
method as previously described, through the 
admission-valve A into the cylinder C. The suc¬ 
tion continues until the piston P reaches the 
position shown in the right-hand view. Then 
the piston returns until it again arrives at the 
position shown in the left-hand view, compress¬ 
ing the charge of mixture during this operation. 
Just before the piston arrives at the end of its 
travel in this direction, the charge of vapor, 
now under compression, is ignited by the 
method previously explained and its expansion 
forces the piston back to the position shown in 
the right-hand view. When the piston has, for 
the second time, reached the position shown in 
the right-hand drawing, a mechanical device 
opens the exhaust-valve. The exhaust-valve 
remains open until the piston has again arrived 
at the position in the left-hand view. Then it 
closes, the piston again commences to draw in 
a charge of vapor and the cycle of operation 
of the motor is repeated. 

Four-Cycle Motor, Operation of. A four¬ 
cycle motor has only one working stroke or im¬ 
pulse for each two revolutions. During these 


290 


The Automobile Handbook 


two revolutions which complete the cycm of 
the motor, six operations are performed: 

1. Admission of an explosive charge of gas, 
or gasoline vapor and air to the motor-cylinder. 

2. Compression of the explosive charge. 

3. Ignition of the compressed charge by a 
hot tube, or an electric spark. 



4. Explosion or extremely sudden rise in the 
pressure of the compressed charge, from the in¬ 
crease in temperature after ignition. 

5. Expansion of the burning charge during 
the working stroke of the motor-piston. 

6. Exhaust or expulsion of the burned gases 
from the motor-cylinder. 

































The Automobile Handbook 


291 


Two-Cycle Motor. The foregoing outline of 
the functions of the parts of the motor prepares 
us for a description of the two-cycle form of 
motor. This particular form of motor draws 
in a charge of gas or vapor, compresses it, fires 
it and discharges the product of combustion or 
burned gases while the crank makes but a sin- 



Fig. 132 


gle revolution, and while the piston makes one 
complete travel backward and forward. 

Fig. 132 shows two sectional views—that is 
to say, views of the motor cut in two, longi¬ 
tudinally—of the principal parts of a two-cycle 
motor. Other parts, such as the crankshaft, 
connecting rod and flywheel, are omitted to 
avoid confusion. C is the crankcase and A 
the admission valve, through which the vapor 














292 


The Automobile Handbooks 


passes to tlie crank case. B is the inlet pas¬ 
sage, through which it passes from the crank 
chamber to the cylinder. P is the piston. The 
igniter, which makes the electric spark when 
the lower point comes in contact with the up¬ 
per, is shown immediately below the cylinder 
cover. This causes the explosion of the vapor. 
E is the exhaust port, through which the burned 
charge escapes after the piston has been driven 
outward by the explosion and has reached the 
end of its stroke. 

Let it be supposed that the motor is still and 
the crank chamber C is full of gas or vapor. 
To start the motor the piston is started by 
means of a crank on the flywheel shaft, and as 
it passes to the position shown in the left-hand 
drawing it forces the charge of vapor through 
the port B into the cylinder. The piston then 
returns to the position shown in the right-hand 
view, moving away from the crank chamber C, 
and in doing so closes the port B and the ex¬ 
haust opening E and compresses the charge of 
vapor. The points of the igniter separate, 
a spark occurs and the resulting explosion 
forces the piston outward again. When the pis¬ 
ton reaches a point near the end of the stroke, 
as shown in the left-hand drawing, it uncovers 
the port E and the burned charge passes out, 
the new charge coming through the port B im¬ 
mediately afterwards. 

The admission of the new charge to the crank 
chamber is controlled by the action of the pis- 


The Automobile Handbook 


293 


ton. As the latter travels outward it has a 
tendency to create a vacuum in the crank 
chamber. This draws the valve inward and 
admits the charge of vapor. 

It will be observed that there is a projection 
on the head of the piston. This is generally 
known as a baffle-plate. Its object is to pre¬ 
vent the incoming charge from passing di¬ 
rectly across the cylinder and out at the ex¬ 
haust port E, which, it will be observed, is di¬ 
rectly opposite it. The baffle-plate directs the 
incoming charge toward the combustion cham¬ 
ber end of the cylinder, providing as nearly as 
may be, a pure charge of vapor and assisting 
in the expulsion of the remainder of the burned 
gases remaining in the cylinder as a result of 
the last explosion. 

Motors —Two and Three Port. In the two- 
port motor, as illustrated in Fig. 133, the func¬ 
tions are as follows: 

The first stroke of the piston produces a vac¬ 
uum in the crankcase and the mixture rushes 
in (as a consequence) through the check valve 
in the motor case. The second stroke com¬ 
presses the mixture, and when the communicat¬ 
ing port is uncovered the mixture surges into 
the cylinder. The next (third) stroke com¬ 
presses the mixture entrapped in the cylinder, 
since the ports are then covered by the piston, 
and at the proper instant the mixture is ignited. 

From this point on it is a normal repetition 
of functions, and once the motor gets under 


294 


The Automobile Handbook 


way it two cycles. The three-port motor, Fig. 
134, differs in that the mixture is taken in 
through a third port uncovered by the piston, 
instead of through a check valve in the case, 
and the details in practice change accordingly. 



Engine, Gasoline, Fuel Consumption of. 
The fuel consumption of a motor is always a 
serious question, and one of importance to the 
purchaser as well as to the manufacturer. 

Ordinarily about one and two-tenths pints of 
gasoline per horsepower hour under full load 
will cover the fuel consumption. That is, when 










































The Automobile Handbook 295 

the mixture is of the proper explosive quality 
and the water comes from the jacket at a tem¬ 
perature of about 160 degrees Fahrenheit. 

The temperature of the water in the jacket 
around the cylinder has a great deal to do with 
the fuel consumption. 

If the water is forced around the cylinder so 
as to keep it cold, the heat from the combustion 
is cooled down so quickly by radiation that the 
expansive force of the burning gases is mate¬ 
rially reduced, and consequently less power is 
given up by the motor. 

The object of the water is not to keep the cyl¬ 
inder cold, but simply cool enough to prevent 
the lubricating oil from burning. The hotter 
the cylinder with effective lubrication the more 
power the motor will develop. 

Engine, Two-Cycle, Fuel Consumption of. . 
The two-cycle engine uses more fuel than the 
four-cycle. The greatest consumption is not so 
much due to the fact that the two-cycle motor 
makes an explosion for every revolution, in 
contrast with the missed stroke of the four¬ 
cycle, as it is to the fact that there is a consider¬ 
able retention in the cylinder of the exhaust 
charge, and that, despite the deflector, more or 
less of the fresh charge escapes at the exhaust. 
The two-cycle is also harder on a battery owing 
to the greater frequency of the demands upon 
it, but with improved methods of ignition, even 
dry batteries have been found to give very sat¬ 
isfactory service. 


296 The Automobile Handbook 

Engine, Sliding Sleeve Type. The Knight 
sleeve valve engine, Fig. 135, is a four cycle 
gasoline engine in which the usual poppett 
valves have been replaced by two concentric 
sleeves sliding up and down between the 
cylinder walls and the piston. Certain slots in 
these sleeves register with one another at proper 
intervals, producing openings between the com¬ 
bustion chamber and the inlet and exhaust 



Fig. 135 

Knight Sliding Sleeve Engine 
manifolds for the passage of fresh gas into the 
cylinder and burned gas from it. 

It will be noted that the two sleeves are inde¬ 
pendently operated by small connecting rods 








The Automobile Handbook 


297 


working from a shaft made with eccentrics. 
This eccentric shaft is driven at one-half 
crankshaft speed, usually by silent chains. This 
shaft takes the place of, and performs the same 



Fig. 136 


Inlet Opening on 
Knight Engine 



Fig. 137 


Inlet Open on 
Knight Engine 


functions as the camshaft in the poppett valve 
engine. The eccentric pins that operate the 
inner sleeves are given a certain advance or 
lead over those operating the outer sleeves. 
This lead, about 90 degrees, together with the 















































298 


The Automobile Handbook 


half-speed rotation of the shaft, gives the fol¬ 
lowing valve action: 

In Figs. 136 to 142 the relative positions 
of the pistons, sleeves and ports are shown in 



Inlet Closing Firing Point 


various positions during the two revolutions of 
the crankshaft that make up one working cycle 
of inlet, compression, power and exhaust 
strokes. Fig. 136 shows the inlet just open¬ 
ing. The port, or slot in the inner sleeve is 
coming up, the port in the outer sleeve is go- 












































The Automobile Handbook 299 

ing down and the passage for the incoming gas 
is formed by the rapidly increasing opening be¬ 
tween the upper edge of the slot in the inner 
sleeve and the lower edge of the slot in the 
outer sleeve. 



Fig. 140 Fig. 141 Fig. 142 

Exhaust Opening Exhaust Open Exhaust Closing 


Fig. 137 shows the inlet fully open. The 
inner and outer slots are exactly opposite each 
other and the inlet opening in the cylinder 
wall. Fig. 138 shows the closing of the in¬ 
let. The cylinder has been filled with fresh 
















































300 


The Automobile Handbook 


mixture and is ready for the compression stroke. 
Fig. 139 shows the position of the sleeves at 
the top of the compression stroke; the com¬ 
bustion space having been completely sealed by 
the expansion rings in the cylinder head above 
and in the piston below. The firing of the mix¬ 
ture takes place at this point. 

Fig. 140 shows the exhaust port just start¬ 
ing to open. The slot in the outer sleeve is 
coming up and the slot in the inner sleeve is 
going down. Fig. 141 shows the exhaust 
ports fully open. The inner and outer slots 
are opposite each other and at the same time 
opposite the cylinder opening that leads to the 
exhaust piping. Fig. 142 shows the closing 
of the exhaust opening and is practically iden¬ 
tical with the position shown in Fig. 136. 
The four strokes of the cycle (inlet, compres¬ 
sion, power and exhaust) have now been com¬ 
pleted, the crankshaft has made two complete 
revolutions and each sleeve has moved up and 
down once. 

The timing of inlet and exhaust opening and 
closing is not different from that ordinarily used 
in poppett-valve engines, but the opening se¬ 
cured with this construction is greater than 
that ordinarily found in the poppett type. Some 
advantage is also gained because of the more 
direct path of the incoming and outgoing gases. 
The timing of the valve openings is not affected 
by spring pressure or engine speed. 


The Automobile Handbook 


301 


Engines, Eight and Twelve Cylinder Types. 
The development of the automobile engine has 
been along the lines of increase in number of 
cylinders and decrease in the size of the indi¬ 
vidual cylinders, without any considerable in¬ 
crease in the total horsepower delivered by 
the engine. This development has resulted in 
the power being delivered more evenly, inas¬ 
much as an impulse is delivered to the crank¬ 
shaft each time a cylinder fires. With the sin¬ 
gle cylinder engine, one impulse was given for 
each two revolutions and with the increase to 
four, six and eight cylinders, the crankshaft 
has received two, three and four impulses for 
each single revolution. The twelve cylinder 
secures a power stroke for each sixty degrees 
revolution of the crankshaft and consequently 
gives six impulses for each revolution. 

The most radical change between former 
types of engine and the eight and twelve cylin¬ 
der types is that of placing the cylinders in 
two equal divisions, and, in place of standing 
vertically, they are placed at an angle of ninety 
degrees in the eight and sixty degrees in the 
twelve. This design does not materially in¬ 
crease the length of the engine over one having 
four or six cylinders of equal size and, of course, 
makes the height somewhat less, due to the in¬ 
clination. While these engines naturally re¬ 
quire additional cylinders, valves, connecting 
rods and pistons, they make use of only one 


802 


The Automobile Handbook 



Eight Cylinder Chassis 


















The Automobile Handbook 303 

crankshaft and generally of but one camshaft. 
No other increase in number of parts or ac¬ 
cessories is necessary, one carburetor, one ig¬ 
nition device and one of each of the other 
power-plant units doing the work for both sets 
of cylinders. 

The mounting and construction of the gener¬ 
ally accepted type of eight cylinder engine is 
shown in Figs. 143 to 145. As will be noted 
from the top view shown in Fig. 143, a space 
is left between the cylinder blocks which pro¬ 
vides suitable location for such fittings as the 
carburetor, the ignition unit and usually the 
lighting dynamo. The valves are located on the 
inside of their respective castings and the re¬ 
sulting position of the caps allows easy re¬ 
moval, inspection and grinding. * 

The center lines of the two cylinder blocks 
intersect at the center of the crankshaft, and, 
as will be noted from the side elevation in 
Fig. 144, the crankshaft itself does not dif¬ 
fer from the usual four-throw type used with 
four cylinder engines. Depending on the type 
of connecting rod construction used, the cylin¬ 
ders in the blocks are set so that corresponding 
ones on opposite sides are exactly opposite or 
slightly offset from each other in a lengthwise 
direction. In any case the connecting rods 
from the two front cylinders fasten to one 
crankpin, while those from the second cylin¬ 
ders are on the next crankpin, and so on for 
those remaining. 


304 


The Automobile Handbook 



Fig. 144 

Side View of Eight Cylinder “V” Type Engine 

















































































The Automobile Handbook 


305 


Three types of construction are in use for 
the lower end of the connecting rods; the most 
commonly used method being shown in Figs. 144 
and 145, in which one rod is straight and of 



Fig. 145 

End View of Eight Cylinder Engine 
the usual pattern while the corresponding one 
is forked and has the two sides of the fork so 
placed that they are on either side of the 
straight member. With this construction, the 
crankpin is surrounded with a sleeve or liner 
of bearing metal and the forked rod is clamped 





















3 06 


The Automobile Handbook 



Pig. 146 

Packard Twelve Cylinder Engine 










The Automobile Handbook 


307 


around this liner so that the liner is held 
tightly by the rod, and the shaft turns inside 
the liner. The end of the straight connecting 
rod has its bearing on the outside of the liner 
just mentioned and therefore has only a recip¬ 
rocating motion on the liner in place of turn¬ 
ing all the way around. The bearing of the 
straight rod on the liner is adjustable, but the 
liner is not adjustable on the crankshaft. 

Another form of connecting-rod construc¬ 
tion forms one of the rods in the usual way 
with an adjustable bearing on the crankpin. 
On the big end of the rod just mentioned is 
a boss that carries a pin similar to a wristpin, 
and on this pin is mounted the bearing of the 
second connecting rod. The end of the second 
rod does hot surround the crankshaft but is 
mounted on the end of the one with the bearing. 

The third form of rod construction is little 
used on eight cylinder types, but is quite com¬ 
mon on twelves. This method uses a complete 
rod end and bearing on each rod, the ends and 
liners being placed side by side so that each con¬ 
necting rod has a bearing on one-half of the 
length of the crankpim The rods are not in 
the same plane and therefore the cylinders are 
offset, the set on one side of the engine being 
a little forward or back of the opposite set. 
This method allows individual adjustment of 
each bearing. 

In engines with either eight or twelve cylin¬ 
ders, the camshaft is mounted directly above 


308 


The Automobile Handbook 


the crankshaft and therefore between the cylin¬ 
der blocks. Two designs are in common use, 
one making use of separate cams for each of 
the sixteen or twenty-four valves, and the other 
using but one cam for the inlet valves of op¬ 
posite cylinders and another cam for the corre¬ 
sponding exhaust valves. With but one cam 
for two valves, the valve plunger rollers do 
not rest directly on the cam, but the plungers 
are operated from rocker arms, hinged at one 
end to the crankcase and having a roller at the 
end that rests on the cam. When individual 
cams are used for each valve, the cams are of 
necessity placed side by side, but the slight 
distance between each pair makes it necessary 
to offset the valves or offset the cylinder blocks 
in a lengthwise direction. 

As mentioned, it is customary to use one car¬ 
buretor with a manifold that divides near the 
instrument with one branch for each cylinder 
block. Some difficulty was met with in provid¬ 
ing suitable ignition for engines with eight or 
twelve cylinders, but this has been overcome 
by improved forms of ignition breakers, by the 
use of two distributors and two breakers in 
some cases and by the adoption of new prin¬ 
ciples of magneto construction in others. When 
it is realized that a twelve cylinder engine run¬ 
ning at 1,800 revolutions a minute (a moderate 
speed) requires 10,800 accurately timed and 
powerful sparks every minute, the reason for 
the difficulty will be seen. 


The Automobile Handbook 309 

In considering the firing order of these en¬ 
gines, it should be borne in mind that an eight 
is similar to two four cylinder engines, side by 
side, while a twelve is similar to two sixes. All 
four cylinder engines fire in one of two orders, 
either 1-3-4-2 or else 1-2-4-3, considering the 
front cylinder as number one. Each set of four 
cylinders in an eight, that is, the left hand set 
and the right hand set fires in one of these 
orders, the only difference with the eight being 
that one of the cylinders of the left hand set 
fires just half way between two on the right, 
while each cylinder on the right fires midway 
between two on the left. The cylinders on 
the left, from front to back are usually desig¬ 
nated as No. 1 Left, No. 2 Left, and so on; 
while those in the right are No. 1 Right, No. 
2 Right, etc. The firing order of a number of 
eight cylinder engines is therefore as follows: 
1L, 4R, 3L, 2R, 4L, 1R, 2L, 3R; in which it 
will be seen that, looking at either the “Ls” 
or “Rs,” they fire 1-3-4-2. 

The principles explained above apply equally 
to the twelve, in which the engine may be con¬ 
sidered as two sixes, each set of cylinders fir¬ 
ing in one of the orders possible for a six. It 
is possible to number all the cylinders in either 
an eight or twelve cylinder engine consecutively 
from 1 up and in this case the front right hand 
cylinder is usually called number one. The 
numbering may then continue from front to 
back on the right hand side, in which case 


310 


The Automobile Handbook 


these cylinders will be numbered from 1 to 6, 
or may pass to the left side, calling the left 



Fig. 147 

Section Through Twelve Cylinder Engine 

front cylinder No. 2, the second one on the 
right No. 3, etc. This last method would bring 






























































































The Automobile Handbook 


311 


all the odd numbers on the left and all the even 
numbers on the right. 

Designating the cylinders of a twelve by the 
numbers 1 to 6 and showing their position by 
letters, a common firing order would be as fol¬ 
lows : 1R, 6L, 5R, 2L, 3R, 4L, 6R, 1L, 2R, 5L, 
4R, 3L. This fires each set in the common or¬ 
der: 1-5-3-6-2-4. 

A twelve cylinder engine is shown in Figs. 
146 and 147, and most of the data given in the 
foregoing pages applies equally to the twelve 
and the eight. The principal difference between 
the two types is that the angle included between 
the cylinder blocks of the* twelve is less than 
that of the eight, thus leaving less space be¬ 
tween the blocks in the location often called 
the “valve alley .’* Because of the smaller 
space between the cylinders, a larger one is 
left outside of the cylinders before the sides 
of the hood are reached. This fact has led to 
the practice on twelves of locating the Acces¬ 
sories, with the exception of the carburetor, 
outside of the cylinder blocks and in the same 
place that they usually occupy on four and 
six cylinder types. 


312 The Automobile Handbook 

Exhaust—Cause of Smoky. Smoke coming 
from the exhaust of a gasoline motor is due to 
one of two conditions: Over-lubrication—too 
much lubricating oil being fed to the cylinder of 
the motor- or too rich a mixture, that is, too 
much gasoline and an insufficient supply of air. 

The first condition may be readily detected 
by the smell of burned oil and a yellowish 
smoke. The second, by a dense black smoke 
accompanied by a pungent odor. 

Expansion—Best Conditions for. The effi¬ 
ciency of the expansion in an engine cylinder 
depends upon the initial volume of the charge, 
the condition of the mixture, the compression 
pressure, the point of ignition, the speed of ex¬ 
pansion and the losses due to radiation. 

The losses due to improper expansion may 
therefore be decreased by making large valves 
and valve passages, but these often mean greater 
heat losses. The losses due to radiation may 
be reduced by increasing the temperature of the 
jacket water, and decreasing the area of the 
cylinder. But if the cylinder wall temperature 
is increased, there are considerable difficulties 
with lubrication, and the increased gain in 
thermal efficiency will be more than offset by 
the increased friction. 

In order to obtain the highest efficiency the 
difference in the temperature of the water en¬ 
tering and leaving the cylinder jacket should 
be a maximum. In practical tests it has been 
found that the best results are obtained when 
the jacket water is near the boiling point. 


The Automobile Handbook 


313 


Frames. The frame of passenger cars is 
made, in practically all cases, from sheet steel 
ranging in thickness from % to % inch and 
pressed, either while hot or cold, into a channel 
section. This type of frame is called pressed 
steel. In rare cases the steel channel is rein¬ 
forced with pieces of wood, while in other con¬ 
structions the body of the frame is made from 
wood and is then reinforced with plates or 
channels of steel. 

Commercial car and truck frames are also 
made from pressed steel in a majority of cases. 
Other constructions employ rolled steel of chan¬ 
nel “I” beam section, these shapes being bent 
to the required forms to suit the general design 
of the car. 

Pressed steel frames are made from carbon 
or special alloy steels, either in the natural con¬ 
dition or heat treated. The Society of Auto¬ 
motive Engineers recommends a choice between 
three grades of steel for pleasure car frames; 
the first being a .15 to .25 point carbon without 
heat treatment and having an elastic limit of 
35,000 pounds per square inch. The second is 
a steel of .20 to .30 point carbon, having in the 
natural state an elastic limit of 40,000 pounds, 
and when heat treated a limit of 60,000 pounds 
to the inch. The third material is a chrome- 
nickel steel of .25 to .35 point carbon, which is 
heat treated and has an elastic limit of 85,000 
pound? per square inch. 

Tbp frame is usually designated as to size 


314 The Automobile Handbook 

by giving the measurement of the outside depth. 
Frames 3 or 3 y 2 inches deep are usually made 
% inch thick; frames 4 inches deep are made 
5/32 inch thick, those 4% to 6 inches deep are 
either x 3 e- inch or % inch thick; all of the above 
being for passenger cars. Should the thickness 
vary from the measurements just given, the 
depth dimension will be changed from the 
nominal size. The width of the flange is never 
less than iy 2 inches for frames up to 4 y 2 inches 
deep and not less than 1 % inches for deeper 
frames. 

The dimension called the drop is measured 
from the top of the side member to the center 
of the front spring bolt hole. The rear end 
rise, often called the “kick-up,’’ ranges from 
2 to 5 inches. A side rail offset is employed to 
allow short turning of the steering wheels, the 
distance back of the front taper that this offset 
commences, being at least 10 inches. 

The frame is completed with a number of 
cross members joining the side rails, these cross 
members being suited in number, size and shape 
to the general design of the car. In some cases 
the power plant is carried upon a small sub- 
frame supported inside of the front portion of 
the main frame, this sub-frame consisting of 
two lengthwise rails carried by two cross mem¬ 
bers, one at the front and the other at the rear 
of the sub-frame. 

Friction. Friction, being the resistance to 
motion of two bodies in contact, depends upon 


The Automobile Handbook 315 

the following laws: It will vary in proportion 
to the pressure on the surfaces; friction of 
rest is greater than friction of motion; the to¬ 
tal friction is independent of the area of the 
contact surfaces when the pressure and speed 
remain constant; and friction is greater be¬ 
tween soft bodies than hard ones. 

The behavior of lubricated surfaces is quite 
different from dry ones, the laws of fluid fric¬ 
tion being independent of the pressure between 
the surfaces in contact, but it is proportional to 
the density of the fluid and in some manner to 
the viscosity. When a bearing is thoroughly 
lubricated it does not seem to make much dif¬ 
ference what the metals are, because there is a 
layer of oil running around with the journal 
and sliding over another layer adhering to the- 
bearing. If, however, the feed fails, or the pres¬ 
sure gets too heavy for the nature of the lubri¬ 
cant, and so squeezes it out, or the temperature 
has risen so high as to affect the body of the 
oil, then the surfaces come into contact and the 
peculiar nature of the contact asserts itself, 
some combinations abrading and seizing more 
readily than others. When the lubrication is 
thorough, the condition of the fluid friction be¬ 
ing realized, the intensity of the load makes less 
difference than w*ould be expected. 

Fuels for Automobiles. Apart from the pos¬ 
sibility of an increase in the fuel resources of 
the world due to some revolutionary discovery, 
the ingredients in any mixed fuel for automo- 


316 


Thi Automobile Handbook 


bile use must be confined to the following list, 
in which, for completeness, gasoline is in¬ 
cluded : 

Gasoline. Average composition, C=84, II— 
16. 

Source, petroleum. 

Boiling point, 50° to 150° Cent. 

Specific gravity, .680 to .720. 

Calorific value, 19,000 B. T. U. 

Latent heat, small. 

Benzine. Average composition, C=92, H 
= 8 . 

Source, coal tar. 

Boiling point, 80° Cent. 

Freezing point, 5° Cent. 

Specific gravity, .899. 

Calorific value, 19,000 B. T. U. 

Latent heat, small. 

Alcohol. Average composition, C=32, H=8. 
0—35. 

Source, vegetable matter, principally corn, 
beets, potatoes, sugar cane. 

Boiling point, 70° Cent. 

Specific gravity, .806. 

Calorific value, 12,600 B. T. U. 

Latent heat, considerable. 

Tar Benzol. Average composition, C=92, 
H=8. % 

Source, a by-product in the manufacture of 
coke. 

Boiling point, 80° to 120° Cent. 

Specific gravity, .895. 


The Automobile Handbook 


317 


Calorific value, 19,000 B. T. U. 

Latent heat, small. 

Kerosene. Average composition, C=85, 
H=15. 

Source, petroleum. 

Boiling point, 150° to 300° Cent. 

Specific gravity, .800 to .825. 

Calorific value, 19,000 B. T. U. 

Latent heat, considerable. 

Motor Spirit, Naphtha, Benzoline, Benzine. 
Average compositnon, C=85, H=15. 

Source, petroleum and shale. 

Boiling point, 60° to 160° Cent. 

Specific gravity, .750. 

Calorific value, 19,000 B. T. U. 

Latent heat, appreciable. 

Methyl Alcohol, Wood Spirit, Naphtha. Av¬ 
erage composition, C=38, H=12, 0=50. 
Source, the distillation of wood. 

Boiling point, 66° Cent. 

Specific gravity, .812. 

Calorific value, 9,600 B. T. U. 

Latent heat, appreciable. 

Acetylene Ethene. Average composition, 
C=92, H=8. 

Calorific value, 25,000 B. T. IJ. 


318 The Automobile Handbook 

Fuel Mixture. The fuel finally used in the 
cylinders of the internal combustion automobile 
engine is composed of varying proportions of 
air and the vapor of one or more of the liquid 
fuels. The pure vapor of any of these liquids 
does not form a combustible mixture until mixed 
with certain proportions of air, the oxygen nec¬ 
essary for burning being thereby supplied. It 
is the function of the carburetor to vaporize the 
liquid fuel and to then mix with the vapor an 
amount of air which will make a correct mixture. 

Many of the questions and problems entering 
into the question of securing correct mixtures 
from present day fuels are of vital interest 
because of the important bearing this feature has 
upon operating costs. In the following pages 
is given much of the information which is neces¬ 
sary in studying the relations of the fuel vapors 
to the air in the mixture, also a number of 
tables of data pertaining to the heating values 
and characteristics of the vapors and gases in 
common use for this purpose. 

Air, Relation of to Gasoline. Owing to the 
fact that automobile gasoline is composed of 
various percentages of the several available 
fractions of hydrocarbon distillates, it is not 
possible to fix an exact basis for the relative 
proportions of air to fuel. However, the aver¬ 
age carbureter is capable of altering the ratio 
of air to fuel over broad ranges, and it is not 
necessary to know the exact ratio in order to 


The Automobile Handbook 


319 


attain the best results. But it is necessary to 
approximate an average ratio as nearly as pos¬ 
sible in designing and adjusting carbureters in 
order to allow for these variations up and 
down. 

The mixture becomes explosive when 10,000 
volumes of air dilute one volume of gasoline, 
but the best results follow when the ratio is 
one volume of liquid gasoline to. 8,000 volumes 
of air. With one of gasoline to 3,500 of air the 
mixture is non-explosive. 

The proper proportions, from a theoretical 
standpoint, are not always best for practical 
use because a mixture slightly weaker than the 
one found by calculation is more economical in 
the use ~of gasoline. Such a mixture, of course, 
reduces the power slightly, but the proportion 
of power lost is much less than the proportion 
of gasoline saved. Because of the differences in 
speed of the mixture and the differences in the 
volume being admitted to the engine, it is almost 
impossible to secure a proportion that will be 
uniformly satisfactory over a range of all engine 
speeds. A larger volume of mixture, at a slow 
speed, may be required in ascending a hill at 
ten miles per hour than in traveling on a level 
road at three times this speed. In the latter 
case, the velocity of the mixture will, however, 
be much greater. It is best to secure a mixture 
that will give satisfactory results from the 
standpoint of power at low and medium speeds 
rather than at high. 


320 


The Automobile Handbook 


Air, Relation of in Gasoline Mixture. Gas¬ 
oline is a somewhat uncertain mechanical mix¬ 
ture of several hydrocarbon (fractional) distil¬ 
lates, in which the compound “hexane ’ 7 is sup¬ 
posed to be the major portion. This compound 
answers to the formula C 6 H 14 , the products of 
combustion of which will be C 0 2 + C O + H 2 0, 
in which C O will not be found if the combus¬ 
tion is complete. A final expression of complete 
combustion will be as follows: 

2 C 6 H 14 X 19 0 2 = 12 C 0 2 + 14 H 2 0. 

Taking into account the atomic weight of the 
elements, the volume of air required in the com¬ 
plete combustion of 1 pound of hexane may be 
set down ^s follows—atomic weight of the ele¬ 


ments involved: 

Carbon (C).. 12 

Hydrogen (H). 1 

Oxygen (0). 16 


The molecular weight of C tf H 14 = 6 X 12 + 
14X1 = 86; the required oxygen will weigh 
(molecular) 19X16 = 304; the ratio of the 
compound hexane, then, to the combining oxy¬ 
gen will be 

304 

Ratio =-= 3.54, nearly. 

86 

Considering 1 pound of hexane, the* weight 
of oxygen required foT its complete combustion 
will be equal to the ratio as above given, i.e., 
3.54 pounds, nearly. 

Since the oxygen is taken from the air, it is 






The Automobile Handbook 


321 


necessary to consider dry air in the attempt to 
determine as to the weight of the same. This 
air, under a pressure of 1 atmosphere, and at a 
temperature of 60 degrees Fahrenheit contains 
0.23 pounds of oxygen, hence the required air= 

3.54 

--■ = 15.39, in pounds. 

.23 

Gasoline, Thermo-dynamic Properties op 
Gasoline and Air. The following table, 10, 
gives the thermo-dynamic properties of gaso¬ 
line and air, and may be of interest, in view of 
the fact that information on this subject is 
sparse, and most of that only theoretical, or 
empirical deductions. 

This table gives the explosive force in pounds 
per square inch of mixtures of gasoline vapor 
and air, varying from 1 to 13 down to 1 to 4, 
also the lapse of time between the point of igni¬ 
tion and the highest pressure in pounds per 
square inch attained by the expanding charge 
of mixture. The tests from which the results 
given were obtained, were made with a charge 
of mixture at atmospheric pressure, so as to 
more accurately note the results, as the mixture 
takes much longer after ignition to attain its 
highest pressure, and is slower also in expand¬ 
ing. 

It may be well to remember that there are no 
jmore heat-units* and consequently no more foot¬ 
pounds of work in a mixture of gasoline and air, 



322 The Automobile Handbook 

under 5 atmospheres compression, than- under 1 
atmosphere compression. 

Flanged or ribbed air-cooled motors will ap¬ 
proach the figures given in the table for the 
initial explosive force for the varying compres¬ 
sions, very closely, while thermal-siphon wa¬ 
ter-cooled motors will come within about 20 
per cent of these results, and pump and radiat¬ 
ing coil cooled motors will come within about 
30 per cent. While it appears that the proper 
thing to do would be to run hot, the repair bill 
will more than offset its efficiency. The last two 
columns in the table give the temperature of the 
burning gases, the first of the two columns the 
actual temperature with the accompanying mix¬ 
ture of gasoline and air, and the second the 
theoretical temperatures, or temperature to 
which the burning mixture should attain, if 
there were no heat losses. 


TABLE 10. 

THERMO-DYNAMIC PROPERTIES OF GASOLINE AND AIR. 


Gasoline, 
Vapor and 
Air. 

Time in 
Seconds 
between 
Ignition 
and 

Highest 

Pres¬ 

sure.* 

Explosive Force in 
Pounds per sq. in. 

Temperature 
of Combustion 
in Degrees 
Fahrenheit.* 

Compression 
in Atmospheres. 

3 

4 

5 

Actual. 

Theo¬ 

retical. 

1 to 13 

0.28 

156 

208 

260 

1857 

3542 

1 to 11 

0.18 

183 

244 

305 

2196 

4010 

1 to 9 

0.13 

234 

312 

390 

2803 

4806 

1 to 7 

0.07 

261 

348 

435 

3119 

6001 

1 to 5 

0.05 

1 270 

360 

450 

3226 

6854 

1 to 4 

0.07 

| 240 

320 | 

400 

2965 

5517 


♦At atmospheric pressure. 





















The Automobile Handbook 


323 


Heat of Combustion. The quantity of heat 
generated by the complete combustion of vari¬ 
ous gases and petroleum products is known 
as the heat value of the fuel, and represents the 
maximum amount of heat that can be obtained 
from a given quantity of the fuel. No accurate 
rule has yet been devised by which to compute 
the heat value of any chemical compound from 
its formula and the heat values of the elements 
of which it is composed. Hence, the heat values 
of compounds must be found by a separate de¬ 
termination for each one in the laboratory. The 
heat developed by the combustion of some of 
the commoner fuels and gases is given in Table 
11. In the case of carbon, the heat developed 
by its complete combustion, forming C0 2 , and 
the heat of its partial combustion to CO, are 
given; also the heat of combustion of CO to 
C0 2 . 

Heat Value of a Mixture. The heat value 
of a mixture may be fo 4 und from the heat val¬ 
ues of the substances of which it is composed 
and the percentage of each substance. If Iq, 
h 2 , h 3 , etc., represent the heat values of the 
substances forming the mixture, and p x , p 2 , p 3 > 
etc. represent the percentage of each substance, 
the heat value of the mixture will be repre¬ 
sented by the following formula: 

hmrrrp.h.+p^+pghg+etc. 

Example.—A certain gas has the following 
composition: 


TABLE 11. 

MIXTURES OF AIR AND GASES, AND RESUITING HEAT OF COMBUSTION. 


324 The Automobile Handbook 


Heat of 
Combustion 

B. T. U. 

per 

Cubic 

Foot of 

Gas at 

62° 

• • 03 • • N .HOOOMO 

• • co • • co • ©_ to^ co 

• . • • • T-1 »-H CO *“* 

B. T. U. 

per 

Pound 

of Fuel 

% 

. -©©©to ■OOCOCO’H 

• OOOOO •NN»0 00 W 

• . O ^f< © CO • © CO 

• • CO 03 00 

.co r-1 '(NCJINHN 

Specific 
Heat of 
Gas at 
Constant 

Pressure 

.21751 

.24380 

3.40900 

.24790 

.21700 

.59290 

.40400 

.37540 

Weight 
Required to 
Burn 1 
Pound of 

Gas 

Pounds 

Air 

34.80 

• GO • © © 

• © • • • 

• 03 • N ^ 

• HH • 

O 

. . © • • t>- • O CO • • • 

. • © • • «Q • ©■*«••• 

. • oo • • • ^ co • • • 

Volume 
Required 
to Burn 1 
Cubic Foot 
of Gas 

Cubic Feet 

Air 

• oo 

. . CO 

• 03 

t . 

• oo . 03 oo © © 

■ CO • to 03 © • • 

• .... LQ r-H 

03 •©-<*«© COH 

o 

• »o • -to • © © to to to 

. . . -(MCOCONC1 

Volume of 

1 Pound of Gas 
at Atmospheric 
Pressure 

Cubic Feet 

O 

<M 

© 

11.88 

13.55 

189.80 

•to ©COtOf^^CO 
•to ©l>-tO©t^© 

•CO O0 CO CO 03 Tt< 

• *H 03 *-4 *—* V* 

o 

03 

CO 

11.20 

12.77 

178.80 

03 ^ © 

• ^hconoj^n 

•03 00 03 03 *—»***< CO 

• t— l 03 < f-4 

Weight 
of Gas 
at 30°, 
per 
Cubic 
Foot 

Pound 

.08927 

.07847 

.00562 

■ -V CO 00 o © CO »-h 

■ O 03 CO CO © © © 
r— co to oo co co 03 

• t'- 03 ^ l>» OO 03 

• © H o © O NO 

4 • . 

hemical Proportions 

.S3 -2 ■ 

Cd O M 

. > • 

|S : s cSoBog 

87 : « 

7 11 : 11 +++J+ 

: o oqogj 

55*3 : £ jSBWSS 

.0 > -o «c 5 .1 a 

gS :ago8s , » i 

++;«"» i? oSSsS 

o 

°"S J+°°+So + tttt 

Sr 3 K ++ o s °« t S ! 5 ! 9 1 9 

Sol oJooo- ouooo 

Fuel 

0 

Oxygen, 0. 

Nitrogen, N. 

Hydrogen, H. 

vai uuu, . .. 

Carbon, C. 

Carbon monoxide, CO. 
Carbon dioxide, CO2.. 

Methane, CH4. 

Ethylene, C2H4. 

Ethane, C2H0. 

Benzol vapors, CeHe.. 
Acetylene, C2H2. 




































































The Automobile Handbook 325 


Constituents of Gas Per Cent. 

Hydrogen, H . 20 

Marsh gas, CH 4 . 70 

Acetylene, C a H 2 . 10 


What is the heat value per cubic foot of the 
mixture ? 

Solution.—Referring to Table 11 , the heat 
values per cubic foot of these gases are seen to 
be 327, 1,010 and 1,464 B. T. U., respectively. 
Apply the formula just given. Pi =: .20, p 2 = 
.70, and p 3 = .10. Also, h x = 327, h 2 = 1,010, 
and h 3 = 1,464. Substituting, hm = .20 X 327 
+ .70 X 1,010 + .10 X 1,464 = 65.4 + 707 + 
146.4 = 918.8 B. T. U. Ans. 

Temperature of Combustion. The theoret¬ 
ical temperature of the combustion of a given 
fuel can easily be calculated. Making no al¬ 
lowance for losses of heat, and supposing that 
just enough air is furnished for the combustion, 
burning carbon should have a temperature 
about 4,940° above zero; while burning hydro¬ 
gen should have a temperature about 5,800° 
above zero. In practice, these temperatures 
are never attained, on account of heat losses. 

Loss of Heat. The loss of heat from any hot 
object is accomplished in three ways: by con¬ 
vection, by conduction and by radiation. In 
all practical cases a body loses heat by a com¬ 
bination of these processes. 

When heat is produced in the cylinder by the 
combustion of the gases, the piston is at or near 
the upper dead center; that is, it remains nearly 
stationary when the heat is greatest and when 





326 The Automobile Handbook 

the heat loss per unit area of inclosing walls is 
most rapid. 

Under the usual conditions of ignition, the 
gas contained in the cylinder must be set into 
violent motion by the spread of the flame 
through it, and this motion will aid the dissipa¬ 
tion of the heat in the gas to the containing 
walls. So convection will be an important fac¬ 
tor in the process and perhaps the principal 
factor. Perhaps a part of the gain in power 
which has resulted, in some instances, from the 
use of multiple ignition may be due to violent 
motion of the gas. Practically all air cooled 
motors have their valves in the head, so the 
charge is contained between the cylinder walls 
and the piston head. 

The heat absorbed by the water-jacket is 
equal to the weight of water passed through the 
jacket multiplied by the temperature range; or, 
in other words, it is the difference between the 
temperature of the water when it enters the 
water-jacket and that of the water when it 
leaves the jacket. For instance, if the tempera¬ 
ture of the entering water is 50° and that of 
escaping water is 180°, the temperature range 
is 180° — 50° = 130°. Then, if the weight of 
the water passing through the jacket in 1 hour 
is 100 pounds, the heat carried away is 100 X 
130 = 13.000 British thermal units. 


The Automobile Handbook 327 

Fuel Feed, Vacuum. 

The Stewart vacuum gasoline tank, Figs. 148 
to 152, consists of two chambers. The upper 
one is the float or filling chamber, and the lower 
one is the reservoir or empty chamber. The 
upper chamber is connected with the intake 
manifold of the motor, and also with the main 
gasoline supply tank. The lower or emptying 
chamber is connected with the carburetor. Be¬ 
tween these two chambers is a valve. The 
suction of the piston on the intake stroke creates 
a vacuum in the upper chamber. This closes 
the valve between the two chambers, and in 
turn draws gasoline from the main supply tank. 
The gasoline, being sucked or pumped up into 
this upper chamber, operates a float valve. 
When this valve has risen to a certain mark 
it automatically shuts off the suction valve and 
opens an air valve. This open air valve creates 
an atmospheric condition in the upper chamber 
and opens the valve into the lower chamber, and 
the gasoline immediately commences to flow to 
the lower or emptying chamber. The lower 
chamber is always open to outside atmospheric 
conditions, so that the filling of the upper cham¬ 
ber in no way interferes with an even, uninter¬ 
rupted flow of gasoline from this lower cham¬ 
ber to the carburetor. 

A is the suction valve for opening and clos¬ 
ing the connection to the manifold and through 
which a vacuum is extended from the engine 
manifold to the gasoline tank. 


328 


The Automobile Handbook 



Stewart Vacuum Fuel Feed Tank 

































The Automobile Handbook 329 

B is the atmospheric valve, and permits or 
prevents an atmospheric condition in the up¬ 
per chamber. See Fig. 149. When the suc- 



Float and Levers of Vacuum Tank 
tion valve A is open and the suction is drawing 
gasoline from the main reservoir, this atmos¬ 
pheric valve B is closed. When the suction 

























330 


The Automobile Handbook 



Arrangement of Parts of Vacuum Fuel Feed 














The Automobile Handbook 331 

valve A is closed, then the atmospheric valve 
B must be open, as an atmospheric condition is 
necessary in the upper tank in order to allow 
the fuel to flow through the flapper valve H 
into the lower chamber. 

C is a pipe connecting tank to manifold of 
engine. 

D is a pipie connecting vacuum tank to the 
main gasoline supply tank. 

E is a lever to which the two coil springs S 
are attached. This lever is operated by the 
movement of the float G. 

F is a short lever, which is operated by the 
lever E and which in turn operates the valves 
A and B. 

G is the float. 

H is flapper valve in the outlet T. This 
flapper valve is held closed by the action of 
the suction whenever the valve A is open, but 
it opens when the float valve has closed the 
vacuum valve A and opened the atmospheric 
valve B. 

•J is a pet cock for drawing water or sedi¬ 
ment out of the reservoir. This may also be 
used for drawing gasoline for priming or clean¬ 
ing purposes. 

K is a line to the carburetor extended on in¬ 
side of the tank to form a pocket for trapping 
water and sediment which may be drawn out 
through pet cock J. 

L is a channel space between inner and outer 
shells, and connects -with air vent R, ihus main- 


332 


The Automobile Handbook 


taining an atmospheric condition in the lower 
chamber at all times, and thereby permitting 
an uninterrupted flow of gasoline to the carbu¬ 
retor. 

M is the guide for float. 

R is an air vent over the atmospheric valve. 
See Fig. 151. The effect of this is the same 
as if the whole tank were elevated and is for 
the purpose of preventing an overflow of gaso¬ 
line should the position of the car ever be such 



■C 


FROM 

GASOLINE 


CUPPiy TANK 


Fig. 151 


Upper Connections of Vacuum Tank 
as would raise the gasoline supply tank higher 
than the vacuum tank. Through this tube also 
the lower, or reservoir chamber, is continually 
open to atmospheric pressure, so that the flow 
of gasoline from this lower chamber to the car¬ 
buretor is always allowed. 

T is the outlet located at the bottom of the 
float reservoir in which is the flapper valve H. 

The flapper valve is ground on its seat and 
should be trouble-proof. A small particle of 
dirt getting under the flapper valve might pre- 





The Automobile Handbook 333 

vent it from seating absolutely air-tight and 
thereby render the tank inoperative: In order 
to determine whether or not the flapper valve 
is out of commission, first plug up air vent; 
then detach tubing from bottom of tank to 
carburetor. Start motor and apply finger to 
this opening. If suction is felt continuously, 
then it is evident that there is a leak in the 
connection between the tank and the main gas¬ 
oline supply or else the flapper valve is being 
held off its seat and is letting air into the tank 
instead of drawing gasoline. 

Any troublesome condition of the flapper 
valve can be remedied by removing tank cover, 
then lift out the inner tank. Fig. 152. The 
flapper valve will be found screwed into the 
bottom of this inner tank. 

Coupling and elbow connections should be 
kept screwed down tight. Care should be taken 
that tubing contains no sharp flat bends that 
might retard the gasoline flow. 

Gasoline for priming or cleaning purposes 
can be obtained by opening pet cock. 

To make certain that the tank is not at fault 
in case of trouble, take out the inner tank en¬ 
tirely. This will leave only the outer shell, 
which will then be nothing more than an or¬ 
dinary gravity tank. Fill this tank with gas¬ 
oline and start to run. If you still have trouble 
it will be apparent that the fault lies elsewhere 
and not in the tank. 


334 


The Automobile Handbook 


Carburetor pops and spits are due to im¬ 
proper carburetor adjustments. Running the 
engine at low speed with an open throttle for 
any length of time might not produce sufficient 
suction to fill the tank when empty. But this 
condition might take place because of dirt or 
foreign matter getting in and clogging the gas¬ 
oline feed tube. 

If you have any doubt as to the tank being 
full of gasoline, it is only necessary to close the 
throttle and the suction of the motor will then 
fill the tank almost instantly. 

To fill the tank, should it ever become en¬ 
tirely empty, close the engine throttle and turn 
the engine over a few revolutions. This will 
create sufficient vacuum in the tank to fill it. 
If the tank has been allowed to £tand empty 
for a considerable time and does not easily fill, 
when the engine is turned over, look for dirt or 
sediment under the flapper valve H, or the 
valve may be dry. Removing the plug W in 
the top and squirting a little gasoline into the 
tank will wash the dirt from this valve; also 
wet the valve and cause the tank to work im¬ 
mediately. This flapper valve sometimes gets 
a black carbon pitting on it, which may tend 
to hold it from being sucked tight on its seat. 
In this case the valve should be scraped with a 
knife. 

If the motor speeds up when the vacuum tank 
is drawing gasoline from the main supply it 
shows that either the carburetor mixture is too 


The Automobile Handbook 


335 


rich, or the connections are so loose that it is 
drawing air into the manifold. There should 



Fig. 152 


Shell of Vacuum Tank 

be no perceptible change of engine speed when 
the tank is operating. 












































336 


The Automobile Handbook 


Gases, Expansion of. All gases expand 
equally, 1/273 part of their volume for each 
degree of temperature, Centigrade, of 1/491 
part of their volume for each degree of temper¬ 
ature, Fahrenheit. 


Gasoline, How Obtained. Benzine/Gasoline, 
Kerosene and the kindred hydro-carbons are 
products of crude petroleum. 

They are separated from the crude oil by a 
process of distillation. The process is very sim¬ 
ilar to that of generating steam from water. 

Crude petroleum subjected to heat will give 
off in the form of vapor such products as Ben¬ 
zine, Gasoline and Kerosene, etc. The degrees 
of heat at which these products are separated 
are comparatively low. Various degrees of heat 
will separate the distinct products. As a means 
of illustration, it may be said that the crude oil 
when raised to certain temperatures gives off 
vapors which when cooled liquefy into oils. 

Viscosity of Gasoline. It is a mistake to 
assume that because gasoline does not thicken 
up, it is not retarded in its flow through the noz¬ 
zle of the carbureter. Taking gasoline having a 
specific gravity of 0.71 the quantity that will 
pass through the nozzle of a carbureter under a 
given pressure will increase as the temperature 
is increased, as shown in the following table: 


Temp, degrees F. 

50 * . 

59° . 

68 * . 

77 * . 


86 

95 


Relative Flow. 

. 1 

. 1.073 

. 1.145 

. 1.212 

. 1.27 

. 1.335 








The Automobile Handbook 


337 


Since carbureter nozzles are not readily ad¬ 
justable, nor with any degree of certainty, it 
follows from the above that the influence of tem¬ 
perature upon the weight of fuel ejected will 
most certainly affect the efficiency of the car¬ 
bureter. This source of trouble goes to indi¬ 
cate that some means of maintaining a constant 
temperature is of the greatest advantage, and 
in a measure it argues for the adaptation of 
water (hot) jacketing, not around the depres¬ 
sion chamber, as is usually the practice, but 
around the gasoline (float) bowl, in order to 
maintain a constant temperature of the liquid 
gasoline as it flows through the nozzle. 

Gasoline Explosions. There are two entirely 
different kinds of explosion, which would un¬ 
doubtedly both be referred to as gasoline ex¬ 
plosions. The real gasoline explosion is the 
kind taking place in the cylinder of a gasoline 
motor, in which heat and pressure are suddenly 
produced by the combustion of gasolipe vapor 
in air. The other kind of explosion referred to 
may be explained as follows: 

If a tank of gasoline be placed on a woodpile 
and the latter set on fire, the heat would 
raise a pressure in the tank, which would rap¬ 
idly increase and the tank would finally explode 
from the pressure. The gasoline would then 
be thrown in. all directions, and, owing to its 
superheated condition, the greater part of it 
at least would instantly vaporize, mix with the 


338 


The Automobile Handbook 


air of the atmosphere and be ignited by the 
flame which caused the explosion. 

Gasoline Fires, Extinguishing. A number of 
fires have been caused by leaky gasoline pipes 
on automobiles, and many persons would like to 
know of chemicals which can be used to put 
out such fires. Water is exceedingly danger¬ 
ous to use, and it is not always possible to get 
at the fire to smother it with wet rags or waste. 

In case of fire due to gasoline, use fine earth, 
flour or sand on top of the burning liquid. 

A dry powder can be used for this purpose 
which will extinguish the fire in a few seconds. 
It is made as follows: Common salt, 15 parts—• 
sal-ammoniac, 15 parts—-bicarbonate of soda, 
20 parts. The ingredients should be thoroughly 
mixed together and passed through a fine mesh 
sieve to secure a homogeneous mixture. 

If by any chance a tank of gasoline takes fire 
at a small outlet or leak, run to the tank and 
not away from it, and either blow or pat the 
flame out. Never put water on burning gaso¬ 
line or oil, the gasoline or oil will float on top 
of the water and the flames spread much more 
rapidly. 

Several gallons of ammonia, thrown in the 
room with such force as to break the bottles 
which contain it, will soon smother the strong¬ 
est fire if the room be kept closed. 

Gears, Horsepower Transmitted by. The fol¬ 
lowing formulas will give the horsepower that 


The Automobile Handbook 


339 


may be transmitted by gears with cut teeth of 
involute form and of various metals. 

H.P = Horsepower. 

P = Pitch diameter in inches. 

C — Circular pitch in inches.* 

F = Width of face in inches. 

R = Revolutions per minute. 

PXCXFXP 

H.P=- ; -(Annealed tool steel.) (1) 


H.P: 


90 

PXCXFXP 


140 


(Mach, steel, or Phos¬ 
phor Bronze.) (2) 


PXCXFXR 

H.P=- (Cast Brass.) (3) 

410 

PXCXFXR 

H.P=- (Cast Iron.) (4) 

550 

Example: Required, the horsepower which 
a tool steel pinjon, 2 inches pitch diameter, 1 
inch face and No. 10 diametral pitch, will 
transmit at 900 revolutions per minute. 

Answer: From .the table the circular pitch 
corresponding to No. 10 diametral pitch is 


♦The circular pitch corresponding to any diametral pitch num¬ 
ber. may be found by dividing the constant 3.1416 by the diam- 
e t r a 1 pitch 

Example: What is the circular pitch in inches corresponding 
to No. 6 diametral pitch. 

Answer: The result of dividing 3.1416 by 6 gives 0.524 Inches 
as the required circular pitch. 







340 


The Automobile Handbook 


0.314. Then by Formula No. 1, 2X0.314X1X 
900 equals 565.2. This, divided by 90, gives 
5.29 horsepower. 

Gear, Internal-Epicyclic. It is often desired 
to ascertain the speed of rotation of the differ¬ 
ent members of this form of gearing. To cal¬ 
culate their speeds, the following formulas are 
given, which, by reference to the letters desig¬ 



nating the different parts in Figure 153, may be 
readily solved. 

Let R be the revolutions per minute of the 
disk or spider carrying the pinions D. 

Let N be revolutions per minute of the gear 
E. 

Let G be the revolutions per minute of the 
internal gear F. 

When the internal gear F is locked and gear 
E rotating, the speed in revolutions per minute 
of the disk or spider carrying the pinions D is 



The Automobile Handbook 


341 


E 

R = N - 

E + F 

If the internal gear be locked and the spider 
carrying the pinions D be rotated, then the 
speed in revolutions per minute for the gear E 
will be 

• E + F 
N = R - 

- E 

If the spider carrying the pinions D be held 
rigid and the gear E be rotated, the speed in 
revolutions per minute for the internal gear F is 

N X E 

G —- 

F 

If the pitch diameter of the gears is not read¬ 
ily obtainable, the number of teeth in each gear 
may be used instead, as the result will be ex¬ 
actly the same. 

It will be recognized that this is the form of 
gearing employed in the older forms of plane¬ 
tary transmission devices. Newer types use no 
internal toothed gears. 

Horsepower. The actual horsepower of an 
engine can only be determined by making a 
test with suitable brakes or dynamometers. 
This method would give the actual brake horse¬ 
power. In order to allow ready calculation, the 
Society of Automobile Engineers’ formula is 





342 


The Automobile Handbook 


used and is generally recognized. The bore or 
diameter of the cylinder is first squared; that 
is, the size in inches is multiplied by itself. This 


TABLE 12 

HORSEPOWER OF GASOLINE ENGINES 

(S. A. E. Four Cycle Formula) 


Bore 

4 cyl. 

6 cyl. 

8 cyl. 

12 cyL 

2 % . 


15.0 

20.0 

30.0 

2 % . 


18.2 

24.2 

36.3 

2% . 


19.8 

26.4 

39.6 

3 . .. 


21.6 

28.8 

43.2 

3% . 


23.4 

31.2 

46.9 

3 % . 


25.4 

33.8 

50.7 

3% . 


27.3 

36.5 

54.7 

3 % . 


29.4 

39.2 

58.8 

3 % . 


31.5 

42.0 

63.1 

3% . 


33.8 

45.0 

67.5 

3% . 


36.2 

48.3 

72.4 

4 . 


38.4 

51.2 

76.8 

4 % . 


40.8 

54.5 

91.7 

4 Vi . 

. 28.9 

43.4 

57.8 

86.7 

4% . 


45.9 

61.2 

91.9 

4% . 


48.6 

64.8 

97.2 

4 % . 


51.3 

68.4 

102.7 

4 % . 


54.2 

72.2 

108.3 

4% . 


57.0 

76.0 

114.1 

5 . 


60.0 

80.0 

120.0 

5 ^4 . 


66.2 

88.2 

132.3 

5 Vi . 


72.7 

97.0 

145.4 


Note: Above powers are calculated for pis¬ 
ton speed of 1000 feet per minute. 


number is then multiplied by the number of 
cylinders and the result divided by 2 y 2 . Thus, 
for an engine with 5-inch bore: 5x5=25. If 
of 4 cylinders, 25x4=^100, and 100 divided by 
2y 2 gives the result as «. A horsepower. In order 
to secure approximately irrect results, the en¬ 
gine is supposed to be c -erating at 1,000 feet 
per minute piston speed. 
























The Automobile Handbook 343 

Many fQrmulae, other than that known as the 
S. A. E., are used in calculating the power of 
internal combustion engines, and it is upon some 
of these that the S. A. E. rating was originally 
based. The methods most used in making such 
calculations, either for four cycle or two cycle 
engines are explained in the following pages. 

Horsepower of Explosive Motors. The first 
requisite is to find the number of power strokes 
made per minute by the motor. In a single 
cylinder motor of the four-cycle type there is 
one power stroke for every two revolutions, 
and if the motor has four cylinders there is 
one power stroke for every revolution of the 
crank shaft. The number of power strokes then 
may be found by the following formula (refer¬ 
ring to a four-cycle motor) : 

C 

N = —XS 
4 

in which N = Number of power strokes per 
minute. 

C = Number of cylinders. 

S = Angular velocity of crank shaft in rev¬ 
olutions per minute. 

Having ascertained the number of power 
strokes per minute, the horsepower is found by 
the formula, 

PLAN 
H.P -- 


33,000 



344 


The Automobile Handbook 


P = Mean effective pressure (M. E. P.). 

L = Length of stroke in feet. 

A = Area of piston in sq. in. 

N = Number of power strokes per minute. 
This formula does not discriminate between 
mechanical friction and losses in “fluid’’ fric¬ 
tion. A formula that is more arbitrary and 
that fits the majority of cases, requiring only 
the use of a few facts, such as diameter of cyl¬ 
inder, length of stroke, and revolutions per min¬ 
ute, is presented as follows: 

VXN 

H.P =- 

10,000 

in which 

Y = volume of cylinder in cu. inches. 

N = number of power strokes per min. 

The constant used varies from 9,000 to 14,000 
depending upon certain types of engines; 10,000 
being an average figure for four cycle engines. 
The brake horsepower will be from 65 to 85 per 
cent of the result obtained; 80 per cent may be 
taken as an average. As an example we may 
take a four-cycle, four-cylinder motor 4%-in. 
bore and 4 1 / ^>-in. stroke making 1,200 power 
strokes per minute. Volume (Y) of cylinder 
equals area of piston 15.9 sq. in. X length of 
stroke 4 1 /2=71.55 cu. in., and multiplying this 
by 1,200 (N) and dividing the product by 10,- 
000 gives 8.05 H.P. Taking 80 per cent of this 
as the brake horsepower the result is 6.44 II P. 



The Automobile Handbook 345 

From a theoretical standpoint a two-cycle ex¬ 
plosive motor should not only have as great a 
speed, but also be capable of developing almost 
twice the power that a four-cycle motor does. 
It is a fact nevertheless that its actual perform¬ 
ance is far different. 

The horsepower of a two-cycle motor may be 
calculated from the following formula, 
D 2 XSXN 

II.P=- 

21,000 

in which 

D=diameter of cylinder in inches. 

S=stroke of piston in inches. 

N=number of revs, per minute. 

Example: Required, the horsepower of a two- 
cycle motor of 4 y 2 inches bore and stroke, with 
a speed of 900 revolutions per minute. 

Answer: The square of the bore multiplied 
by the stroke is equal to 91.125, which multi¬ 
plied by 900, and divided by 21,000, gives 3.91 
as the required horsepower. The results given 
by the above examples agree very closely with 
those obtained from actual practice. 

Horsepower, Electrical. One electrical horse¬ 
power is equal to the current in amperes multi¬ 
plied by the electro-motive force or voltage of 
the circuit and divided by 746. 

Let C be the current in amperes and E the 
voltage of the circuit. If E. H. P. be the re¬ 
quired electrical horsepower, then 



346 


The Automobile Handbook 


EXC 

E.H.P—- 

746 

In practice with motors of small power, 1,000 
watts are necessary to deliver one mechanical 
or brake horsepower at the driving shaft of the 
motor. 

If the actual or brake horsepower of an elec¬ 
tric motor be known, the efficiency of the motor 
may be readily found by the following formula : 

If E be the voltage of the circuit and C the 
current in amperes consumed by the motor, let 
B. H. P be the brake horsepower of the motor 
and e the efficiency of the motor, then 

B.H.P X 746 


e = 


EXC 




The Automobile Handbook 


347 


Ignition Systems. 

Ignition. In order that an explosive motor 
may operate economically, and with the highest 
percentage of efficiency, it is absolutely neces¬ 
sary that two objects shall be attained, viz.: A 



Fig. 154 

Coil and Timer Ignition With Storage Battery 


correct mixture of the gasoline and air, and that 
this mixture be correctly ignited at the proper 
time. 





































348 


The Automobile Handbook 



Coil and Timer With Dry Cells. A, Switch. B, 
Dry Cells. C, Condenser. D, Timer. E, Con¬ 
tacts. F, Armature. G, Core of Coil. H, Pri¬ 
mary Winding. I, High Tension Winding. J, 
Spark Plug. 


C 



Coil Vibrator Principle. A f Core of Coil. B, Arma¬ 
ture of Coil Magnet. C, Adjusting Screw. D, 
Trembler Blade. E, Contacts. 















































The Automobile Handbe^k 


349 



Fig. 157 

Coil Vibrator Details. A, Adjustment. E, 'Tension 
Spring. C, Trembler Blade. D, Holding Screw. 
E, Contact Bridge. F, Contact Blade.' <i, Lock¬ 
ing Screw. 





































350 


The Automobile Handbook 



Connecticut Storage Battery Ignition Wiring 


TrewinoN .switch 



Circuits Through Remy Battery Ignition System 





































































The Automobile Handbook 


351 


Induction Coil. Induction is the process by 
which a body having electrical or magnetic 
properties calls forth similar properties in a 
neighboring body without direct contact. This 
property is known as self-induction, and is 
caused by the reaction of different parts of the 
same circuit upon one another, due to varia¬ 
tions in distance or current strength. The cur¬ 
rent produced by an induction coil has a very 
high electro-motive force, and hence great 
power of overcoming resistance. 


f\ / 


/ \ / 


\ 

V —*-^ 

SWITCH - + BATTER* 


ll -14-U. 


( VJKJKJKT ) 

'-- y 

SWITCH + -BATTERY 
INDUCTION COIL 


Fig. 160. 

If a current of electricity be caused to flow 
through a straight conductor forming a part of 
a closed electric circuit, lines of force, com¬ 
monly called magnetic whirls or waves, are in¬ 
duced in the air and rotate around th$ conduc¬ 
tor. 

If the current of electricity be flowing in the 
circuit and through the straight conductor from 








352 


The Automobile Handbook 


right to left, as shown in the upper view in Fig. 
160, the lines of force or magnetic whirls will 
rotate around the conductor from left to right, 
or in the direction of the hands of a clock. On 
the other hand, if the conditions be reversed 
and the current flows from left to right the lines 
of force or magnetic whirls will rotate from 
right to left, as shown in the lower view in Fig. 
160. The direction of rotation of these lines 
of force or magnetic whirls may be positively 
determined by the use of a galvanometer, an 
electric testing instrument having a needle simi¬ 
lar in appearance to that of an ordinary com¬ 
pass. Upon placing this instrument in the 
path of the lines of force and making and 
breaking the battery circuit by means of the 
switch, the needle of the galvanometer will be 
deflected from its zero point in the direction of 
the rotation of the lines of force. If the direc¬ 
tion of the flow of the electric current through 
the circuit be changed by reversing the poles of 
the battery, the needle of the galvanometer will 
be deflected from its zero point in the opposite 
direction. Whether these lines of force or mag¬ 
netic whirls rotate continuously around the wire 
has not been demonstrated. They rotate with 
sufficient force to be tested by the galvanometer 
only until the electric current in the closed 
circuit has reached its maximum value after 
closing the circuit; that is to say, only during 
the infinitesimal space of time required by the 
current to reach its full value or power. 


The Automobile Handbook 


353 


If, instead of a straight conductor, a loop of 
insulated wire, in the form of a circle, be until- 
ized for the passage of the current, as at A and 
B in Fig. 161, the lines of force will still rotate 
around the wire as shown, their direction being 
dependent on the direction of the electric cur¬ 
rent. If the electrical circuit be provided with 



a current reverser, or device for changing the 
battery connections in the circuit from positive 
to negative and vice versa, the lines of force can 
be made to rotate rapidly first in one direction 
and then in the other, as indicated in Fig. 160. 

Suppose this loop of insulated wire be com¬ 
posed of a great number of turns, it then be- 

















354 


The Automobile Handbook 


comes a coil or closed helix, and as all the lines 
of force cannot pass between the turns of the 
electrical conductor forming this helix they 
must pass completely through the helix instead 
of rotating around a single loop, as at A and B, 
Fig. 161. If the current flows through the con¬ 
ductor in the direction indicated by the ar¬ 
rows, at C in Fig. 161, and over and around the 
coil in the direction shown, the lines of force 
will flow through the coil towards the observer, 
and complete their path or circuit through the 
air, returning into the coil at the opposite end. 
If the current be reversed and flow around the 
coil in the direction of the hands of a clock, the 
lines of force will flow through the coil in the 
opposite direction, that is, away from the ob¬ 
server, as at D, Fig. 161. 

This form of coil or closed helix may be des¬ 
ignated as the primitive form of an electro¬ 
magnet. When forming part of a closed elec¬ 
tric circuit it possesses the property of magnet¬ 
izing a bar of wrought iron placed within it. 
If a short round bar of wrought iron be placed 
a short distance within the coil, and the battery 
circuit be closed, the iron bar will, if the cur¬ 
rent is sufficiently strong, be sucked or drawn 
into the center of the coil, and a considerable 
effort will be required to withdraw it. 

The object of the bundle of soft iron wires, 
which form the core of any form of spark coil, 
is to increase the magnetic effect of the lines of 


The Automobile Handbook 355 

force or magnetic flux, or rather to reduce the 
resistance to their passage through the coil. 

As has been previously stated, when a current 
of electricity flows through a conductor of wire 
forming a coil or closed helix, lines of force are 
induced and flow through, and also around the 
exterior of the coil. In a like manner, when the 
electric circuit is broken, the lines of force sud¬ 
denly reverse their direction, and travel through 
the coil with a tremendous velocity until they 



Principle of Atwater Kent Battery Ignition 


reach a state of neutralization. During this re¬ 
verse travel of the lines of force through the 
coil, a current of electricity is induced in the 
winding of the coil, but in the opposite direction 
to that in which the battery current was flowing. 
The effect of this induced current, which is of 
far greater intensity or pressure than the bat- 














356 


The Automobile Handbook 






















































































































































































































The Automobile Handbook 


357 


tery current which induced it, is to form an arc 
or spark at the breaking point in the circuit. 

Secondary Spark Coil. Fig. 163 shows the 
secondary or jump-spark form of coil. It is 
composed of an iron core and a primary winding 
similar to that described in conjunction with 
Fig. 162, with the addition of an outer winding 
of many turns of fine wire. This wire, of very 
small size, is known as the secondary winding, 
varying in diameter from No. 36 to No. 40 B. & 
S. Gauge, and in length from 5,000 to 10,000 
feet. In the drawing the induction coil is 
shown equipped with an electro-magnet make 
and break, or vibrator device, which is the form 
mostly used for ignition purposes. The other 
form, known as the plain jump-spark coil, has a 
mechanically operated make and break device 
attached to the motor to operate the coil. 

The arc or spark produced at the breaking 
point of the electrical circuit in which the pri¬ 
mary winding of the coil is connected is not 
utilized for ignition purposes in this type of coil,. 
When the circuit is broken the sudden reaction 
or backward flow of the lines of force or mag¬ 
netic flux in the iron core produce an induced 
current in the secondary winding, but in the 
opposite direction to that of the battery cur¬ 
rent. This induced current is of so much 
greater intensity and velocity than that induced 
in the primary winding by this same reaction, 
that the arc or spark induced in the secondary 
winding of the coil will jump across a space 


358 The Automobile Handbook 

from one end of the wire to the other, varying 
from % inch to as much as 8 or 10 inches in 
length, dependent upon the length of wire in 
the secondary circuit, the electro-motive force 
of the battery and the frequency of the inter¬ 
ruptions or number of times per minute the 
electric circuit is made and broken. 

Referring to Fig. 163 A is the core, B the pri¬ 
mary winding and C the secondary. The two 
coils are held in place upon the core by the 
washers D. The primary wire B is wound over 
a paper tube E, and the secondary wire C is in¬ 
sulated from the primary wire by a mica insu¬ 
lating tube F. The coil proper is enclosed in a 
wood case G. 

The terminals or binding posts on top of the 
case G are connected with the ends of the sec¬ 
ondary wire 1 and 2. The secondary terminals 
are plainly indicated by the letter S’. In the 
base H of the coil case is the condenser J, an 
essential feature of this form of coil, which 
utilizes the induced primary current to produce 
a greater reactive energy in the secondary 
winding. 

At the right-hand end of the coil and outside 
the casing G is located the electro-magnetic vi¬ 
brator or trembling device, which automatically 
makes and breaks the primary circuit. The 
end 3 ®f the primary wire is connected with the 
contact screw K through the bracket L. The 
spring M, carried by the bracket N, with screw 
O, is connected with the terminal or binding 


The Automobile Handbook 


359 


post P, immediately beneath it, by the wire 6 
through the bracket N". The end 4 of the pri¬ 
mary wire is connected with another terminal 
or binding post P, at the other end of the base 
of the coil. The condenser J is connected 
across the contact points of the screw K and 
the spring M, by the w T ires 5 and 6 and screws 
Q and X. The condenser is composed of a num¬ 
ber of sheets of tinfoil V, laid between sheets 
of specially insulated paper I, with the opposite 
end of every alternate sheet of tinfoil projecting 
from the paper insulation, as shown. These 
projecting ends are connected together, and by 
the wires 5 and 6 to the contact screw K and 
spring M, respectively, as previously described. 

When the coil is connected in, or forms part 
of a closed electric circuit by means of the ter¬ 
minal or binding posts P, on the base of the 
coil, the current flows through the primary 
winding B. This instantly produces a high de¬ 
gree of magnetism in the core A, and the pole- 
piece T of the core extension R becomes strongly 
magnetic and attracts the iron button W of the 
spring M. This draws the spring M away from 
the end of the screw K, and in consequence 
breaks the electric circuit. This results in the 
demagnetizing of the pole-piece T and the con¬ 
sequent return of the spring M to its normal 
position in contact with the end of the screw K. 
So long as the electric circuit remains closed 
this operation is repeated at a very high rate 
of speed. The effect of this continuous opera- 


360 The Automobile Handbook 

tion of the coil is to produce an intermittent 
current in the secondary winding of high inten¬ 
sity and velocity. If wires are placed in the 
holes in the small terminals or binding posts on 
the top of the coil and brought within a short 
distance of each other, a stream of sparks will 
pass from one wire to the other in a peculiar zig¬ 
zag manner and emit a loud, crackling noise, 
accompanied by a peculiar odor, caused by the 
formation of ozone through the electro-chemical 
action of the spark. 

Under ordinary circumstances the arc or 
spark which occurs on the breaking of the con¬ 
tact between the platinum points of the screw 
K and spring M would not be utilized, but by 
means of the condenser in the base, which is 
connected to these parts, as before described, 
the static charge of electricity generated by this 
action is stored in the condenser. When the 
contact is again made this stored electric energy 
is given up or discharged by the condenser and 
flows through the primary winding of the coil 
in connection and in the same direction as the 
battery current and increases the magnetic ef¬ 
fect of the core A enormously. 

The construction and operation of the con¬ 
denser is fully described under the heading 
Condenser. It should be understood that this 
is one of the most important elements of the 
ignition system, whether battery or magneto 
type, and its care should never be neglected if 
efficient ignition is desired. 


The Automobile Handbook 


361 


Commutators, Ignition. The commutator of 
the ignition system of a multi-cylinder gaso¬ 
line motor has a three-fold use: To switch the 
battery current in and out of the electrical cir¬ 
cuit at the proper time—To transfer the bat¬ 
tery current successively from one coil to an¬ 
other—To vary the point or time of ignition 
of the explosive charge in the motor cylinder. 
The commutator of the Ford car is shown below. 














362 


The Automobile Handbook 


Distributors. Instead of employing a sepa¬ 
rate spark coil for each cylinder of a multi¬ 
cylinder engine, the primary circuits of which 
are made and interrupted in rotation, a device 
known as the distributer may be used, which 
permits of any number of cylinders being 
sparked from a single coil. In magnetos de¬ 
signed for jump spark ignition of multi-cylin¬ 
der engines the distributer forms part of the 
magneto and is rotated by it. The distributer 
is nothing more than a timer of secondary cur¬ 
rent, and generally consists of a cylindrical shell 
of insulating material, upon the inside of the 
cylindrical surface of which equidistant metal¬ 
lic segments in number equal to the motor cyl¬ 
inders are inserted. A conducting arm rotat¬ 
ing upon a shaft concentric with the insulated 
shell carries a brush, which successively makes 
contact with the segments. The arm is in per¬ 
manent electrical connection with the free sec¬ 
ondary terminal of the coil, and each one of 
the segments is wired to the spark plug of a 
cylinder. 

In the case of four-cylinder motors the 
moving arm is geared at one-half the speed of 
the motor, thus making contact for each cyl¬ 
inder once in each two revolutions or complete 
cycle. 

In battery ignition systems the distributor 
is mounted directly above the breaker and 
the distributor rotating member is driven from 
the same shaft which operates the breaker. 


The Automobile Handbook 


363 


Ignition—Timing. In timing the ignition of 
a motor one should base his operations on one 
particular cylinder, and this should be the most 
accessible one. Let it be assumed that a me¬ 
chanic is required to test or correct the timing 
of a. four-cylinder, four-cycle vertical engine. 
He would have to know the order in which the 
cylinders fired, and how to find the firing center 
of No. 1 cylinder. As the operation of the 
valves on most motors may be readily seen, the 
firing center and the order in which the cylin¬ 
ders fire can be easily learned from the action 
of either set. For instance, if on turning the 
motor over slowly the intake valve of No. 1 
cylinder opens and closes, then that of No. 3 
cylinder, and following No. 3 that of No. 4 op¬ 
erates, the mechanic need go no further, for he 
knows that the engine fires 1-3-4-2. The ex¬ 
haust valves, of course, may be used in the same 
way. However, if the valves are entirely en¬ 
closed, as on the Winton cars, open the priming 
or relief cocks, and beginning with cylinder No. 
1 note the order in which the air is forced out 
through the cocks. There are two rules for 
finding which cylinder is on its firing center, 
that are based on the action of the valves; these 
are as follows: When an exhaust valve is open 
the following cylinder is about to fire. When 
an intake valve is open the previous cylinder is 
about to fire. One very simple method of find¬ 
ing the firing center of a cylinder is to open 
the priming cocks of all the cylinders but one, 


364 The Automobile Handbook 

turn the motor over slowly till compression is 
encountered, open the cock, insert a stiff wire 
till it rests on the piston head, then carefully 
bring the piston to the top of its stroke. The 
cylinder will then be on its firing center. When 
the firing center, and the order in which the cyl¬ 
inders fire are known, all that remains to be 
done in timing an engine is to set the revolving 
segment of the commutator or distributer so 
that a spark will occur in the proper cylinder 
when the spark control lever is advanced about 
one-third or, with the spark control lever fully 
retarded, and the piston about y 2 to 1 inch 
down on the explosion stroke, set the segment 
so that it just begins to make contact. 

Many troubles arise from faulty or defective 
insulation. 

A wire placed too close to an exhaust-pipe 
invariably fails after a time, owing to the insu¬ 
lation becoming burnt by the heat of the pipe. 

A loose wire hanging against a sharp edge 
will invariably chafe through in course of time. 

If the insulation of the coil breaks down it 
cannot be repaired on the road, it should be re¬ 
turned to the makers. A slight ticking is 
usually audible inside the coil when this occurs. 

All wires where joined together should be 
carefully soldered, the joints being afterwards 
insulated with rubber or prepared tape. Never 
make a joint in the secondary wires. See that 
all terminals are tightly screwed up. When 
connecting insulated wire, the insulation must 


The Automobile Handbook 365 

be removed, so that only the bare wire is at¬ 
tached. Wires sometimes become broken, and 
being loose make only a partial contact. 

Battery terminals frequently become cor¬ 
roded; they should be covered with vaseline, 
and require periodical cleaning. See that all 
connections at the battery are clean and bright. 

The porcelain of the spark plug may be 
cracked and the current jumping across the 
fracture. The points may be sooty and require 
cleaning. They may be touching and require 
separating, or they may be too far apart. The 
usual distance between the points is about one 
thirty-second of an inch, which is approxi- 
n ately the thickness of a heavy business card. 

Clean all oil and dirt from the commutator. 
Most commutators are so placed as to give the 
maximum possible opportunity to collect oil 
and dirt. They should always be provided with 
a cover. 

In course of time dry or storage batteries 
will become weak or discharged. Always carry 
an extra set. 

Spanners, oil-cans, tire-pumps, etc., have been 
known to get on the top of the batteries, 
thereby connecting the terminals together and 
causing a short-circuit. 

The platinum contacts of the coil may be¬ 
come corroded. They should be cleaned with a 
small piece of emery cloth or sandpaper. 


366 


The Automobile Handbook 


Ignition, Atwater Kent. This*device is de¬ 
signed to draw from a battery, as nearly as 
oossible, only the electrical energy necessary 
to ignite the charge, and to keep the batteries 
until the energy remaining in then} is too small 
to produce an effective spark. Its principal 
constituent parts are, a jump-spark coil and 
condenser, a primary contact maker, the time 
of which may be advanced or retarded, and a 
high tension distributer. Its distinguishing 
features are— 

a. But one spark is made for each ignition. 

b. The primary contact, rupture of which 
produces the spark, is exceedingly brief, no 
longer in fact than is actually required to build 
up the magnetism in the core of the spark coil. 

c. The duration of this contact is independ¬ 
ent of the engine speed in the same way that 
the contact of the ordinary coil vibrator is. 

d. Contact is made and broken mechanically 
through a shaft driven by the engine, conse¬ 
quently a spark may be obtained from a bat¬ 
tery that is too weak to operate a vibrator. The 
mechanism by which the instantaneous primary 
contact is produced is similar to a snap contact 
produced by a small spring-controlled hammer 
pulled out of position by a ratchet on the shaft. 
The ratchet has as many teeth as there are cyl¬ 
inders, and runs at the camshaft speed. When 
used with a two-cycle engine, it runs at the 
crankshaft speed if there are four cylinders. If 
there are two cylinders, it runs at half the en- 


The Automobile Handbook 367 

gine speed and the ratchet has four teeth. The 
ordinary commutator is not used in connection 
with it, but a driving connection must be made 
from the crankshaft or camshaft to the vertical 
shaft of the spark generator itself, which is 
mounted on the back of the dashboard. 

The Atwater-Kent system consists of three 
parts: 1, The unisparker, which combines the 
special form of contact-maker, which is the 
basic principle of this system, and a high ten¬ 
sion distributor. 



Atwater Kent Timer Before Moving Lever 

2, The coil, which consists of a simple pri¬ 
mary and secondary winding, with condenser—■ 
all imbedded in a special insulating compound. 
The coil has no vibrators or other moving parts. 

3, The ignition switch. 

The operation of the unisparker is shown in 
Figs. 164 to 167. This consists of a notched 
shaft, one notch for each cylinder, which ro- 


368 


The Automobile Handbook 


tates at one-half the engine speed, a lifter or 
trigger which is pulled forward by the rotation 
of the shaft and a spring which pulls the lifter 
back to its original position. A hardened steel 
latch and a pair of contact points complete the 
device. 



Fig. 165 

Atwater Kent Timer Before Lever Escapes 


The figures show the operation of the con¬ 
tact-maker very clearly. It will be noted that 
in Fig. 164 the lifter is being pulled forward 
by the notched shaft. When pulled forward as 
far as the shaft will carry it, Fig. 165, the 
lifter is suddenly pulled back by the recoil of 
the lifter spring. In returning it strikes 
against the latch, throwing this against the con¬ 
tact spring and closing the contact for a very 
brief instant—far too quickly for the eye to 
follow the movement, Fig. 166. 


The Automobile Handbook 369 

Fig. 167 shows the lifter ready to be pulled 
forward by the next notch. 

Note that the circuit is closed only during 
the instant of the spark. No current can flow 
at any other time, even if the switch is left 
“on” when the motor is not running. 

By means of the distributor, which forms the 
upper part of the unisparker, the high-tension 
current from the coil is conveyed by the ro¬ 
tating distributor block, which seats on the end 
of the unisparker, to each of the spark plug 
terminals in the order of firing. 



Fig. 166 

Atwater Kent Timer With Contacts Closed 


Where the lighting and starting battery is 
used for ignition, two wires from the ignition 
system should run directly to the battery ter¬ 
minals. They should not be connected in on any 
other branch circuit. 


370 


The Automobile Handbook 


The automatic type is cylindrical in shape 
and consists of a pressed steel casing with a 
hard rubber cap, the latter forming the base 
of the high-tension distributor. The device is 
mounted on a shaft which is driven at half the 
speed of the crankshaft. Within the casing is 
located the mechanism, consisting of the gov¬ 
ernor which automatically controls the advance, 
the circuit breaker and high-tension distributor. 



Atwater Kent Timer With Contacts Re-opened 

At the bottom of the casing is the governor, 
a modification of the centrifugal type which 
consists of two pairs of weights, each pair be¬ 
ing pivoted together at their centers, and two 
double arm brackets. When the shaft starts 
to revolve, the weights extend away from the 
center and the arms change their angular re¬ 
lation in direct proportion to the- speed of the 
driving shaft. 


The Automobile Handbook 


371 


In order that the weights will not move away 
from the center too easily and give too great 
an advance to low speeds, the brackets carry¬ 
ing the springs are so arranged that the weights 
have to act against them when obeying the im¬ 
pulse of centrifugal force, and moving away 
from the axis of rotation. Virtually each 
weight is a bell-crank lever with one point of 
connection pivoted to the arm and the other 
point of connection pivoted to the weight. The 
four weights thus give four bell-crank levers 
working in the same direction at the same time 
against the four respective springs. 

In timing with automatic advance the piston 
in No. 1 cylinder should be raised to high 
dead center, between compression and power 
strokes, then, with the clamp which holds the 
unisparker loose, the unisparker should be 
slowly and carefully turned backwards, or 
counter clockwise (contrary to the direction of 
rotation of the timer-shaft), until a click is 
heard. This click happens at the exact instant 
of the spark. Now clamp the unisparker tight, 
being careful not to change its position. 

Now remove the distributor cap, which fits 
only in one position, and note the position of 
the distributor block on the end of the shaft. 
The terminal to which it points is connected to 
No. 1 cylinder. The other cylinders in their 
proper order of order of firing are connected to 
the other terminals in turn, keeping in mind the 
direction of rotation of the timer shaft. 


372 The Automobile Handbook 

When timed in this manner the spark oc¬ 
curs exactly on “center” when the engine is 
turned over slowly. At cranking speeds the 
governor automatically retards the spark for 
safe starting, and as the speed increases, the 
spark is automatically advanced, thus requir¬ 
ing no attention on the part of the driver. 

The first operation in timing the hand ad¬ 
vance unisparker is to crank the engine until 
the piston of No. 1 cylinder is on high dead 
center between the compression and power 
strokes. 

The unisparker is then placed on the shaft, 
the advance rod from the steering post being 
connected to the lug on the side of the uni¬ 
sparker, which is provided for that purpose. 

The position of the spark advance lever on 
the steering wheel sector should be within y 2 
inch of full retard, and the connecting levers 
should be such as to give the unisparker a 
movement of at least 45 degrees to 60 degrees 
for the full range of spark advance. 

After the spark lever is connected up and the 
unisparker is in position it should be left loose 
at the driving gear, and, with the motor on 
dead center as above directed, the shaft of the 
unisparker should then be turned forward or 
in the same direction as that in which the timer 
shaft normallv rotates, until a click is heard, 
at which point it should be set by tightening 
the driving connection. 

The contact points are the only adjustable 


The Automobile Handbook 


373 


feature of the unisparker. These points should 
never touch when engine is at rest and the 
space between them should vary from 1/100 
to 1/64 of an inch, depending upon the strength 
of the batteries, spark, heat required, etc The 
spark can be made hotter by decreasing the dis¬ 
tance, and current can be economized by in¬ 
creasing it. Once or twice a season these con¬ 
tacts should be examined and should be kept 
flat and bright by means of a small file or 
emery cloth on a stick. The proper adjustment 
when starting with new batteries is about 1/32 
of an inch, if dry cells are used. If storage 
battery is used, it may be necessary to reduce 
this a little. At intervals of six or eight hun¬ 
dred miles of service as the batteries decrease 
in strength, these contacts should be closed from 
a quarter to a half turn, or until regular fir¬ 
ing is obtained. Do not attempt under any cir¬ 
cumstances to adjust the tension of the springs. 

Frequently when high-tension wires are run 
from the distributor to the spark plugs through 
metal or fibre tubing, trouble is experienced 
with missing and back-firing, which is due to 
induction between the various wires in the tube. 
This trouble is especially likely to happen if 
the main secondary wire from the coil to the 
center of the distributor runs through this tube 
with the spark-plug wires. 

Wherever possible, the distributor wires 
should be separated by at least y 2 inch of space 
and should be supported by brackets or insu- 


374 


The Automobile Handbook 


lators rather than run through a tube. In no 
case should the main distributor wire be run 
through a conduit with the other wires. 

If irregular sparking is noted at all plugs, 
examine first the battery and connection there¬ 
from. If the trouble commences suddenly, it 
is probably due to a loose connection in the 
wiring. If gradually, the batteries may be» 
weakening or the contact points may require 
attention. See that the contacts are clean and 
bright, and also that the moving parts are not 
gummed with oil or rusted. 

Atwater Kent Closed Circuit System. The 
construction of an Atwater Kent breaker which 
operates on the closed circuit principle is shown 
in Figure 168. 

The contact carrying arm is short and light 
and is acted upon at its free end by the cam, 
rather than at the center as is the more usual 
practice. The condenser has been mounted on 
the breaker base in place of in the coil as with 
some former installations, thus eliminating some 
of the outside wiring. 

The distributor does not differ in principle of 
operation from former types. The distributor 
rotor just clears the points with which the spark 
plug wires connect and the high tension current 
jumps this minute gap. 

The coil used with this system consists of the 
usual core with primary and secondary windings 
which are sealed into an insulating tube. On 
top of the coil is located a small length of iron 


The Automobile Handbook 


375 


wire, called the resistance unit, which is in series 
with the primary ignition circuit. With exces¬ 
sive flow of current because of the switch being 
left closed while the engine is idle or for any 
other reason, this wire heats and increases its 
resistance sufficiently to prevent a damaging heat 
at the breaker contacts or in the coil windings. 

The gap between the contact points of the 



breaker may be adjusted by sliding the bar 
which carries one of the contact points. This 
bar is held by a screw and with this screw 
loosened the necessary change may be made. 
The normal gap between the points with the 
end of the contact arm on the high point of a 
cam lobe should not be greater than six thou¬ 
sandths of an inch. 








376 The Automobile Handbook 

Ignition, Connecticut. The Connecticut au¬ 
tomatic igniter system, Fig. 168, produces a 
single spark upon a break occurring in the pri¬ 
mary circuit which, though being closed, has 
energized a coil. This break is effected in the 
igniter by means of a cam revolving against a 
breaker arm. The high tension spark is dis¬ 
tributed in the same instrument. The igniter 
is mounted on a vertical shaft running at half 
engine speed irrespective of the number of 



Pig. 169 

Connecticut Breaker Mechanism 
cylinders. The breaker arm is insulated from 
the base. This provides a metallic circuit; or 
in other words, no engine ground need be uti¬ 
lized in the primary or battery circuit, as the 
primary winding is insulated from the second¬ 
ary ground in the coil. In this case there is 
no possibility of the ignition being affected 
through grounding or shorts in any other cir- 




The Automobile Handbook 


377 


cuit of the car, such as disarrangement in light¬ 
ing or starting systems. 

The igniter may be taken apart and reas¬ 
sembled without the aid of any tools. The dis¬ 
tributor case can be removed by unsnapping the 
two spring clips on the side, thus exposing the 
distributor arm carrying the carbon brush. 
Fig. 169, which can be slipped off the shaft. 



Connecticut Distributor Rotor 

Then remove cotter pin passing through shaft 
and the dust proof cover carrying the upper 
bearing can be taken off and the breaker box 
complete, Fig. 170, can be lifted from the shaft. 
As the shaft is not disturbed the timing is in 
no way affected when the igniter is reassembled 
on the shaft. 
















378 


The Automobile Handbook 


The system is not recommended for use on 
dry cells except as an emergency, but is de¬ 
signed to operate from a storage battery 
charged by a dynamo. 

The automatic switch of the Connecticut 
automatic igniter system is a feature that is 
individual to this system and unique in igni¬ 
tion apparatus. Its function is to kick off the 
switch should the primary circuit be closed an 
unwarranted length of time, as in the case of a 
car being left with the switch on the engine 
stopped. This will prevent the draining of 
batteries. 

Another purpose is to protect the ignition 
wiring should a disarrangement occur in the 
lighting or starting circuit and an excessive 
and destructive amount of current be introduced 
into the ignition circuit. 

The circuit is closed in the automatic switch 
through contacts of the plunger type. These 
plungers are held in contact by a slotted lock¬ 
ing plate. This plate is released by the “off” 
button on the switch; or in cases of prolonged 
or excessive flow of current, by a vibrating 
magnetic release thermostatically effected. The 
construction is such that no amount of outside 
vibration or jar can in any way affect the lock¬ 
ing plate. 

This automatic “kick off” is accomplished 
thermostatically and is a mechanism that has 
been employed for many years in telephone 
switches. 


The Automobile Handbook 379 

To time the igniter, turn the engine over, 
with petcocks open, until the piston of the first 
cylinder has reached the top of the compres¬ 
sion stroke. Now advance the spark lever on 
the steering wheel about three-quarters of the 
way. Remoye distributor cap, then set the 
igniter on driving shaft with set screws loose, 
connect advance lever, turn hub of igniter on 
shaft in direction of rotation until contact points 
are just open, which is the point at which the 
spark takes place, then tighten the hub set 
screws. Replace the distributor cap, carefully 
noticing which segment of the distributor the 
brush is opposite, for this is the connection to 
the spark plug of No. 1 cylinder. Connect 
up the balance of the spark plugs in their fir¬ 
ing order. After connecting all wires you are 
then ready to try out the ignition. Before 
cranking, fully retard your spark lever. To 
suit individual requirements, it may be neces¬ 
sary to slightly advance the igniter hub if 
greater speed is required, or slightly retard it 
for very slow speed. 

This igniter is completely housed and pro¬ 
tected. Little care is required to keep it in 
working condition. About every four or five 
thousand miles the distributor cap should be 
removed and wiped out. On the ball-bearing 
igniter, the distributor arm should be with¬ 
drawn and one or two drops and no more of 
good oil injected into the hole in the end of 
the shaft which carries the distributor arm. 


380 ' The Automobile Handbook 

This will lubricate the lower ball-bearing. No 
other parts need oiling. Care should be taken 
to see that oil does not reach the contact points. 
On the plain bearings or self-lubricating type, 
the bearings require no attention whatever. 

The contact points will probably require no 
attention until run at least ten thousand miles 
and in some cases they may operate for over 
thirty thousand miles without attention. 

The points do not require refiling or clean¬ 
ing even though they may be very rough and 
irregular, but when they become so badly 
burned as to cause missing they should then be 
renewed, in which case proceed as follows: 

Remove the distributor cap and arm' discon¬ 
nect advance lever and wires, remove cotter pin 
in igniter shaft, then spring washer and fibre 
washer, and lift the housing from its shaft. 

The contact adjustment screw will be noticed 
under the dust ring, it being locked from turn¬ 
ing by a hexagon nut on the screw inside near 
the end. Care should be taken to see that this 
nut is tightened up snugly after making a re¬ 
placement or adjustment. When it is necessary 
to adjust these points they should be set so 
that when the roller rests on the point of the 
cam, they open about the same as a magneto 
interrupter. It is not necessary, however, to 
make this adjustment as accurately as on a 
magneto. The adjustable contact screw can 
be removed by taking off the lock-nut and then 
screwing it back out of the housing. 


The Automobile Handbook 


381 


The contact on the breaker arm is riveted 
into it and a complete new arm is necessary in 
making a replacement. 

This arm can be readily removed by taking 
out the small cotter pin in the end of the stud 
on which it moves, remove small fibre washers 
and the arm can then be lifted out. 

When replacing the arm on the stud before 
putting the cotter pin in place, he sure and re¬ 
place the little fibre washers which rest on the 
top of the arm just under the little cotter pin 
and the fibre washer on the stud in the bottom 
of the cup. 

Ignition, Delco. The Delco system of bat¬ 
tery ignition makes use of a combined breaker 
and distributor usually mounted on, and driven 
from, the lighting dynamo or motor-dynamo. 
In some installations the ignition unit is placed 
by itself, but the construction and operation is 
the same in either case. 

The distributor and timer are driven through 
a set of spiral gears attached to the armature 
shaft or its extension. The distributor con¬ 
sists of a cap or head of insulating material, 
carrying one high-tension contact in the center, 
with similar contacts spaced equi-distant about 
the center, and a rotor which maintains con¬ 
stant communication with the central contact 

The rotor carries a contact button which 
sends the secondary circuit to the spark plug 
in the proper cylinder. 


382 


The Automobile Handbook 


Beneath the distributor head and rotor is the 
timer, Fig. 171, which is provided with a screw 
in the center of the shaft, the loosening of which 



Fig. 171 


Delco Ignition Head Breaker. A, Cam Holding 
Screw. B f Battery Current Contacts. C t 
Breaker Cam. D, Resistance Wire Spool. E, 
Cam Contact Levers. M, Dynamo Current Con¬ 
tacts. 


allows the cam to be turned in either direction 
to secure the proper timing, turning in a clock¬ 
wise direction to advance and counter-clock¬ 
wise to retard. 













The Automobile Handbook 383 

The spark occurs at the instant the timer 
contacts are opened. 

The adjustment screw must always be set 
down tight after the cam is adjusted. 

The same weight which operates the arm on 
the regulating resistance also operates the auto¬ 
matic spark control. In addition to the auto¬ 
matic spark control, a manual spark control 
is provided, which is operated by the lever on 
the steering column, and is connected to the 
lever at the bottom of the motor generator. 
The manual spark control is for the purpose of 
securing the proper ignition control for vari¬ 
able conditions, such as starting, differences in 
gasoline and weather conditions. The auto¬ 
matic control is for the purpose of securing the 
proper ignition control necessary for the varia¬ 
tions due to speed alone. 

The resistance unit is a coil of resistance wire 
wound on a porcelain spool. Under ordinary 
conditions it remains cool and offers little re¬ 
sistance to the passage of current. If for any 
reason the ignition circuit remains closed for any 
considerable length of time, the current passing 
through the coil heats the* resistance wire, in¬ 
creasing its resistance to a point where very lit¬ 
tle current passes, and insuring against a waste 
of current from battery and damage to the igni¬ 
tion coil and timer contacts. When the arm 
that cuts the regulating resistance into the 
shunt field circuit is at the top position (that 
is, at high speeds), the resistance unit is cut 


384 


The Automobile Handbook 


out of the ignition circuit. This increases the 
intensity of the spark at high speeds. 

To time ignition: Fully retard the spark 
lever. Turn the engine so that upper dead 
center on flywheel is about one inch past dead 
center with No. 1 cylinder on the firing stroke. 
Loosen screw in center of timing mechanism 
and locate the proper lobe of the cam by turn¬ 
ing until the button on the rotor comes under 
the high tension terminal for No. 1 cylinder. 
Set this lobe of the cam so that when the back 
lash in the distributor gears is rocked forward 
the timing contacts will be open, and when the 
back lash is rocked backward the contacts 
will just close. Tighten screw and replace rotor 
and distributor head. 

If the motor fires properly on the “M” but¬ 
ton, but not on the “B” button, the trouble 
must be in the wiring between the dry cells or 
the wires leading from the dry cells to the com¬ 
bination switch, or depleted dry cells. 

If the ignition works on the “B” button and 
not on the “M” button, the trouble must be 
in the leads running from the storage battery 
to the motor-generator, or the lead running 
from the rear terminal on the generator to the 
combination switch, or in the storage battery 
itself, or its connection to the frame of the car. 

If both systems of ignition fail and the sup¬ 
ply of current from both the storage battery 
and dry cells is ample, the trouble must be in 
the coil, resistance unit, timer contacts or con- 


The Automobile Handbook 385 

denser. This is apparent from the fact that 
these work in the same capacity for each sys¬ 
tem of ignition. 

The following directions for upkeep apply in 
a general way to the “M” or “Mag” igni¬ 
tion on all of the Delco systems, but do not 
apply to the dry battery ignition. 

The contact points are of tungsten metal, 
which is very hard and requires a very high tem¬ 
perature to melt. These should be kept clean and 
smooth on the faces. This can be done by hold¬ 
ing in a vice and using fine emery cloth held 
underneath a flat file. They should be so ad¬ 
justed that when they are open they are apart 
ten-thousands of an inch and the contact arm 
should move about fifteen-thousands of an 
inch after the contacts close. 

The most common causes of contact trouble 
are due to the following: (1) Resistance 
unit shorted out, resulting in excessive current 
through the contacts, especially at low speeds. 
(2) Abnormally high voltages due to run¬ 
ning without the battery or with a loose con- 
- nection in the battery circuit. (3) A broken 
down condenser. 

The distributor head should be properly lo¬ 
cated, that is with the locating tongue of the 
hold-down clip in the notch on the distributor 
head. The head should be kept wiped clean 
from dust and dirt and in some cases it is 
advisable to lubricate this head with a small 
amount of vaseline. 


386 


The Automobile Handbook 


The rotor should be kept free from dust and 
dirt and the rotor button polished bright. The 
rotor button should be fully depressed before 
putting on the distributor head to make sure 
the spring will allow the button to go down to 
the proper level and not subject it to undue 
pressure on the distributor head. 



Delco Closed Circuit System. The closed 
circuit type of breaker used in recently manu¬ 
factured equipment is shown in Figure 172. 
The device consists of a straight arm fitted with 
a small bumper against which the lobes of the 
cam strike when the contacts are to be sepa¬ 
rated. The contacts are normally held closed 
by a long flat spring attached to the pivoted 
end of the arm. 






The Automobile Handbook 387 

The position of the cam may be altered for 
timing purposes by loosening the screw in its 
center which allows the cam itself to be turned 
about its shaft. One of the contacts is adjust¬ 
able to secure the proper opening by turning 
the screw on which it is mounted. The adjust¬ 
ment is maintained by tightening a lock nut. 
The proper break of these contacts when held 
apart by the lobe of the cam is eighteen thou¬ 
sandths of an inch. During the first few hun¬ 
dred miles driving the wear of the fibre block 
on the breaker arm is much greater than after 
this block has worn to a seat. The contacts 
should be adjusted once or twice during the first 
season’s operation of the car, after which but 
little attention will be required. 

In setting the breaker cam for timing, the 
proper lobe of the cam should be located by 
turning, with the center screw loosened, until 
the distributor rotor comes under the position 
which number one high tension terminal on the 
distributor cover occupies when the cover is 
properly located. With number one piston at 
ignition top center this lobe of the cam should 
b’e set so that when the play of the driving gears 
is rocked forward the contacts will be open, and 
when rocked backward the contacts will just 
close. 


388 The Automobile Handbook 

Ignition, Remy Battery. This make of igni¬ 
tion equipment is furnished in two principal 
types, one of which might be called ‘ 1 magneto 
type” and the other one a “vertical ignition 
head.” 

The magneto type of battery equipment bears 
a very close resemblance to the breaker and dis¬ 
tributor end of a separate unit magneto, being 
composed of a distributor having terminals for 
the spark plug leads and below the distributor 
a breaker exactly similar in construction to that 
with magnetos. In connection with this unit 
a two-way switch is used, giving either dry bat¬ 
tery or generator as a source of ignition current. 
To transform the current to one of high-ten¬ 
sion a separate coil is used. 

This coil differs from ordinary coil construc¬ 
tion inasmuch as both ends of the primary wind¬ 
ing are insulated, so that, in the event of a 
ground occurring in the lighting or starting cir¬ 
cuits, the ignition will be unaffected. The coil 
is provided with a safety gap as a further 
means of protection. 

The coil is wound for six volts and is to be 
used in connection with a storage battery or 
with five dry cells. The coil is to be mounted 
on the crankcase within 6 or & inches of the 
breaker points as the condenser is incorporated 
in the coil and not on the generator. A special 
top plate is provided to securely hold coil in 
position. 

The circuit breaker platinum points may be 


The Automobile Handbook 389 

inspected by removing the Bakelite housing 
cover. The points should have a smooth, clean r 
flat surface at all times. The break, or gap, of 
these points should be from 15 to 20 thou¬ 
sandths of an inch. The circuit breaker may, 
if desired, be removed without the aid of tools. 

The high-tension current is distributed to the 
spark plug cables by means of a hard carbon 
brush making contact with distributor segments. 
Neither distributor nor brush will require any 
attention whatsoever. 



Remy Vertical Ignition Timer 


An oiler is provided for the distributor shaft, 
—only a few drops of light oil every one thou¬ 
sand miles will suffice. 

The use of spark plugs which permit of the 
points being adjusted to a definite gap is recom¬ 
mended. The gap between the points should be 
from 20 to 25 thousandths of an inch. 







390 


The Automobile Handbook 


If the motor misses when running idle or 
pulling light, the plug gaps should be wider. 
If motor misses at high speed or when pulling 
heavy at low speed, the plug gaps should be 
made closer. 

The vertical ignition head consists of a com¬ 
bined breaker and distributor mounted in one 
case, Fig. 173, and adapted to be driven from a 
vertical shaft usually on or near the lighting 
dynamo. 

Some of these distributors have a manual ad¬ 
vance for the spark, while some are built with 
a mechanism which automatically advances the 
spark to meet the requirements of the engine 
upon which it is installed. 

The high-tension current is distributed to the 
spark plug leads by a segment which revolves 
close to, but does not touch, the pins in the dis¬ 
tributor head. 

Either iridium-platinum, tungsten or silver is 
used in the contact points, the choice depending 
upon which is best suited to the installation. 

The coil furnished with this system has a spe¬ 
cial ventilating base which may be bolted se¬ 
curely to the engine frame. Its current con¬ 
sumption is limited by a resistance located on 
top of the coil and which is in series with the 
primary winding. 

The metal base of the coil makes an electrical 
connection with the engine or car frame for one 
side of the secondary winding. Therefore, it is 
very important before mounting the coil to see 


The Automobile Handbook 391 

that all foreign matter, such as dirt, grease, 
paint, etc., is removed from the place where the 
coil is to be mounted. It is also very important 
that the base of the coil be fastened down se¬ 
curely at all times. 

The switches furnished with this equipment 
are arranged to reverse the direction of current 
flow through the circuit breaker each time the 
ignition is used. 

It is absolutely necessary that the ignition 
switch be placed in the “off” position when the 
engine is not running. If it is left in the “on” 
position, current from the storage battery will 
be dissipated in the ignition coil which, if con¬ 
tinued, will exhaust the battery. 

By an insulated system is meant one in which 
the circuit breaker is not grounded. By glanc¬ 
ing at the wiring diagram it will be seen that 
the circuit from the switch around through the 
breaker box and back to the switch again is not 
grounded, and that the switch reverses the di¬ 
rection of the current flow through this circuit 
at each quarter turn. 

If the insulation is worn off any one of the 
wires and the copper touches any of the metal 
parts of the car, a short circuit, will result which 
will either render the system inoperative by 
burning out a fuse or will discharge the bat¬ 
tery. A periodical inspection should be made of 
all wiring to see that it is not rubbing or chafing 
on any of the metal parts of the car and that all 
connections are tight and secure. 


392 The Automobile Handbook 

The contact screw should be adjusted with 
the wrench furnished with the system, so that 
the maximum opening of the points is .020 to 
.025 inch, or the thickness of the piece riveted 
upon the side of the wrench. The rebound 
spring should be at least .020 of an inch from 
the breaker arm when the points are at their 
maximum opening. 

To obtain the best results the spark-plug gaps 
should be adjusted to .025 of an inch. 

Ignition, Westinghouse. Dual ignition is 
obtained in the Westinghouse system; that is, 
the battery is an independent source of supply, 
as well as the generator operating with the bat¬ 
tery, while the interrupter, ignition coil and 
distributer are common to both. 

The * interrupter is so constructed that the 
period of contact is practically the same at any 
speed. The spark voltage, therefore, does not 
fall off at high speeds, but is practically the 
same at all speeds. 

Automatic spark advance is a feature of the 
Westinghouse generator. The automatic ad¬ 
vance works over a range of 45°. Provision is 
made for manual operation also, and it is recom¬ 
mended that this be connected up, but the spark 
lever need not ordinarily be touched after the 
original adjustment, the automatic device taking 
care of all adjustments in running. * 

The interrupter is mounted on the generator 
shaft and contacts are operated by a centrifugal 
device that automatically adjusts the spark ad- 


The Automobile Handbook 393 

vance to the speed, keeps the period of contact 
nearly constant at all speeds and prevents any 
inequality between the two interruptions that 
occur in succession during, each revolution. 



Fig. 174 

Westinghouse Ignition and Lighting Dynamo 

The ignition outfit consists, in addition to the 
lighting system and storage battery, of a dis¬ 
tributer and an interrupter, which are made a 
part of the generator, Fig. 174, and an ignition 
coil and switch. The ignition coil transforms 
the six volts of the battery up to the high ten¬ 
sion required for the spark plugs. The inter¬ 
rupter closes and then opens the ignition cir¬ 
cuit at each half revolution of the generator 
shaft, and the distributer directs the high-ten¬ 
sion current to each of the spark plugs in suc¬ 
cession. 











394 The Automobile Handbook 

The operation of the ignition system, includ¬ 
ing the interrupter and distributer, ignition coil 
and switch, begins with the “making” of the 
primary circuit of the coil when the centrifugal 
weights push down the fibre bumper, allowing 
the interrupter contacts to close, Fig. 175. Then 
the weight moves off the fibre bumper, allowing 
the contacts to suddenly separate or open, when 
a high voltage is induced in the secondary of 
the ignition coil and directed by the distributer 



Westinghouse Ignition Breaker, Low Speed Po¬ 
sition 

to the proper spark plug, causing a spark. As 
the speed of the engine increases, the weights 
are thrown out from the center and automatic¬ 
ally advance the time of closing or opening the 
interrupter contacts, and hence advance the 
spark, Fig. 176. At the same time, due to their 
shape, they keep the contacts closed during a 
greater part of the revolution when running at 
high speed; this makes the period of contact 











The Automobile Handbook 


395 


practically the same at all speeds and prevents 
the spark voltage from falling off at high 
speeds. 

To connect the ignition system to the circuit, 
insert the plug into the ignition switch and 
move the switch handle to the “on” position. 



Westinghouse Ignition Breaker, High Speed Po¬ 
sition 

In inserting the ignition plug pay no attention 
to the position of the brass contact pieces on 
the plug. It is desirable that the contacts will 
average up as often in one as in the other of the 
two possible positions, as this reverses the direc¬ 
tion of the current through the interrupter con¬ 
tacts and greatly increases their life. 

The spark plug should be set with slightly less 
than 1/32 inch between tips for best operation. 
Oily or carbonized plugs will often cause miss¬ 
ing, and if dirty, they should be well brushed 
inside and outside with gasoline and wiped per- 














396 The Automobile Handbook 

fectly dry. A crack in the insulating material 
will, of course, probably lead to failure of spark 
in the cylinder. 

The interrupter stop is adjusted so as to give 
the proper pressure on the bumper. When the 
engine is not running and the weights are in a 
closed position, there should be a space of 3/64 
inch between the bumper lever and the stop. 
After the stop is adjusted, the contact screw 
should be adjusted by means of a wrench, so 
that with the cam lever against the upper stop, 
the contacts are open .005 inch. After setting 
for this separation, tighten the clamping screw 
so that the contact screw is held firmly. Be sure 
that the contacts open up positively and that 
the moving element moves clear up against the 
upper stop when released, with some spring ten¬ 
sion still remaining to hold it in this position. 
See that the contacts are kept free from all oil 
and grit. 

Interrupter weights should turn freely on 
their supporting pins and should also clear the 
centrifugal weight spring support by approxi¬ 
mately .01 inch. They should show no lost mo¬ 
tion between the two interlocking weights. In 
making any readjustments, be careful that when 
the engine is turned over very slowly by hand, 
both weights depress the moving part of the 
interrupter enough to definitely close the con¬ 
tacts, otherwise there will be a tendency to miss 
fire in every second cylinder, especially at low 
speeds and if the contacts are worn more or less. 


The Automobile Handbook 397 

When the weights are in the inner position, 
the springs should just touch the fibre-covered 
pins on the weights without exerting any appre¬ 
ciable pressure over that required to just posi¬ 
tively return the weights to the innermost posi¬ 
tion. If necessary to adjust these springs, al¬ 
ways bend the supporting arms and not the 
springs themselves. 

Distributer brushes should slide freely in 
their holders and the springs should push them 
out so as to extend from the holder about *4 
inch when the distributer plate is removed from 
the generator. These brushes should, however, 
be retained firmly by their springs so as to never 
tend to fall completely out of the tubes. Be 
sure that both these brushes are in place in the 
distributer. 

Distributer plate should be kept clean and 
free from carbon dust between brushes and con¬ 
tact surfaces by an occasional wiping. Any 
pitting of the distributer which is in advance 
of the contacts, indicates that the distributer 
gear is set one tooth or so too far back against 
the direction of its rotation. This may cause 
intermittent firing of the cylinders at the higher 
speeds, with consequent loss of power. The 
gear is set correctly at the factory, and if this 
setting is not disturbed the above trouble will 
not be encountered. 

Thfe distributer gear is meshed with the pinion 
on the generator shaft so that the mark at the 
edge of the gear lines up with the tooth of the 


398 The Automobile Handbook 

pinion that is slightly beveled. In coupling the 
generator to the engine, place the piston of 
cylinder No. 1 on dead center at the end of the 
compression stroke. Remove the distributer 
plate and turn the generator back so that the 
line of the distributer brushholder block corre¬ 
sponds with the line on the end bracket. Couple 
the engine and generator shafts while in this 
position. 



Westinghouse Vertical Ignition Head 

The Westinghouse vertical ignition unit can 
be used for ignition from storage batteries or 
plain lighting generators, Fig. 177. This set 
































The Automobile Handbook 


399 


contains interrupter, spark coil and condenser, 
and distributer, all in one unit. One wire from 
the battery or generator to the ignition unit and 
one wire to each spark plug are all that are 
required. 



Westinghouse Vertical Ignition Wiring 

The interrupter, located at the lower end of 
the set, has the same type of circuit-breaker as 
that on the Westinghouse ignition and lighting 



























































400 The Automobile Handbook 

generators, but no automatic spark advance fea¬ 
ture. It can be used equally efficiently for either 
direction of rotation without change. The in¬ 
terrupter is enclosed by a spring collar which 
can be readily removed for inspection or adjust¬ 
ment of the contacts. The collar makes a tight 
joint and is clamped by a screw which prevents 
it from slipping. See wiring diagram, Fig. 178. 

The Westinghouse Ford vertical ignition unit 
is made up of four essential parts, namely, the 
interrupter, the condenser, the induction coil, 
and the distributer, all included in one case. 

The operation of the interrupter can be ob¬ 
served by loosening the thumbscrew and sliding 
upward the loose section of the insulation case, 
which forms the interrupter cover. 

With the ignition switch turned to the “on” 
position and the engine turning over, each seg¬ 
ment of the interrupter cam in turn passes on 
and off the fibre bumper. As each cam passes 
off the bumper, the interrupter contacts close, 
closing the circuit from the battery to the pri¬ 
mary winding of the induction coil. Then as 
they pass on the bumper, the contacts are 
opened, suddenly opening the circuit, thus in¬ 
ducing a high voltage in the secondary of the in¬ 
duction coil. This voltage is directed by the 
distributer on the top of the ignition unit to 
the proper spark plug, causing a spark at the 
spark gap of the plug inside the cylinder, and 
igniting the charge therein. 

The contact screw should be adjusted with, a 


The Automobile Handbook 


401 


screwdriver so that, with the cam against the 
bumper, the contacts are open .008 inch. 

If the contacts show pitted or irregular sur¬ 
faces they should be smoothed up with a very 
fine file, making certain that the surfaces come to¬ 
gether squarely after adjustment has been made. 


402 


The Automobile Handbook 


Ignition, Magneto Type. Magneto ignition 
makes use of a separately mounted machine 
having its own armature and field magnets (per¬ 
manent magnets) and being driven from the 
engine. A magneto always consists of a rotat¬ 
ing member, this being a shuttle wound arma¬ 
ture in most cases, or simply pieces of iron in 
the inductor type. This rotating member, 
through the change in the path of the lines of 
(force from the magnets, produces a current in 
a coil separate or on the armature in the 
shuttle wound form, or mounted separately in 
the inductor magneto. This current rises from 
zero to its maximum voltage twice for each 
revolution of the magneto shaft, one impulse 
flowing in one direction through the windings 
and the next one (on the other half revolution) 
flowing in the opposite direction. The current 
from a magneto always reverses its direction in 
this way and is, therefore, an alternating cur¬ 
rent. The current from a lighting dynamo does 
not reverse its direction and is a direct current. 
For this reason no magneto can ever be used for 
charging a storage battery, a battery requiring 
current that always flows in one direction 
through the circuit. 

Each of the current waves or alternations in 
the magneto circuit is utilized for the produc¬ 
tion of a spark; the breaker contacts opening at 
or near the time when the voltage and flow of 
current is at its maximum, thus producing a 
high pressure in the secondary circuit. 


The Automobile Handbook 


403 


Combined with the armature and the perma¬ 
nent steel magnets that provide the field for 
the magneto is a breaker mechanism that inter¬ 
rupts the flow of current through the circuit 
whenever a spark is desired, and also a dis¬ 
tributor that carries the contacts for delivering 
the high-tension current through the wires that 
lead to the spark plug in the cylinder that is 
ready to fire. While the details of construction 
of magnetos differ as described in the following 
pages, all types contain the parts described 
above. A shuttle wound armature with a break¬ 
er mounted on its shaft is shown in Fig. 179. 



Fig. 179 


Shuttle Type Magneto Armature With Breaker 
The breaker may take any one of several 
forms, a commonly used construction being 
shown in Fig. 180. The circuit is completed 
through the contacts A, one of which is solidly 
mounted, and the other one attached to the mov¬ 
able arm B. The arm carries a fibre block that 
strikes a stationary cam when it is revolved on 
the armature shaft, and inasmuch as the arm is 
pivoted, the contacts are separated to interrupt 
the circuit and cause a spark to come from 
the winding of the high tension coil of the sys- 






404 The Automobile Handbook 

tem. The fine winding that forms the high ten¬ 
sion coil may be wound around outside of the 
armature winding on the shuttle type, or may 
he mounted in a housing separate from the 
magneto. "With the high tension coil on the 
armature, the magneto is self-contained and pro¬ 
duces a spark without outside parts, being called 
a true high tension magneto. Those magnetos 
using outside coils generate the current in their 



Fig. 180 

Magneto Breaker 


armature and send it through the heavy wind¬ 
ing of the separate induction coil, or trans¬ 
former coil. This separate coil has also a fine 
wire winding in which the high tension spark 
plug current is induced by the breaking of the 
circuit through the heavy wire when the break¬ 
er on the magneto opens. 

The system known as “ single ignition/ * when 
using a magneto, comprises a true high tension 









The Automobile Handbook 405 

machine from which wires lead to the spark 
pings. The only other wire required is one to 
the switch that will allow the driver to stop the 
production of sparks by connecting the arma¬ 
ture winding to the frame of the car, or ground¬ 
ing it. No other source of current is provided 
with single ignition. 

4 ‘Double ignition” provides a true high-ten¬ 
sion magneto, as described, and in addition, a 
complete, and entirely separate, battery, timer 
and coil system with a separate set of spark 
plugs and wiring. 

“Dual ignition” uses a magneto similar to 
the single ignition high-tension type, but pro¬ 
vides an additional breaker and induction coil 
through which current may be led from a set 
of dry cells or a storage battery, thus providing 
a source of current other than that of the 
magneto armature when desired for starting or 
emergency use. 

“Transformer coil ignition” makes use of a 
magneto that produces in its armature, or by 
inductor action, a current of low voltage that 
is led to a separately mounted transformer, or 
induction coil. The coil is connected by wires 
to the breaker and distributor on the magneto. 

How to Remove and Replace a Magneto. 
“When about to replace or remove a magneto it 
is well to see that all separable parts are prop¬ 
erly marked, and if not, mark them. This may 
be done with a center punch, cold chisel, letters 
or numerals. In Pig. 181 is shown the guide 


406 The Automobile Handbook 

marks generally used in connection with a high- 
tension magneto of a four-cylinder motor. The 
center punch marks C, on the Oldham coupling 
such as is usually employed on the magneto 
shaft between the magneto and its driving gear, 
serve as a guide in replacing the magneto. All 
that is necessary in replacing a high-tension 
magneto so marked on a four-cylinder, four¬ 
cycle motor is to see that the marks are directly 
opposite each other; but in two or six-cylinder 
motors, where the crankshaft and the armature 
of the magneto do not run at the same speed, 
care must be taken either not to move the 
crankshaft while the magneto is off or to check 
up the timing before it is replaced. In the 
same illustration is shown the method of mark¬ 



ing the timing gears. These marks are made 
with a cold chisel and are generally present in 
up-to-date construction. 







The Automobile Handbook 


407 



Fig. 182 

Figs. 182 and 183 

Bosch High Tension Magneto, Type “DU”. 1, 

Armature End Plate for Primary Winding Con¬ 
nection. 2, Breaker Fastening Screw. 3, 
Breaker Contact Block. 4, Breaker Disc. 5, 
Long Platinum Contact Screw. 6, Short Plati¬ 
num Contact Screw. 7, Flat Sipring for Breaker 
Lever. 8, Breaker Lever. 9, Condenser. 10, 
Collector Ring for High Tension Current. 11, 
High Tension Carbon Brush. 12, Carbon Brush 
Holder. 13, Conductor Bar Terminal. 14, Con¬ 
ductor Bar. 15, Distributor Brush Holder. 16, 
Distributor Carbon Brush. 17, Distributor Plate. 
18, Central Contact on Distributor. 19, Brass 
Segment. 20, Terminal for Spark Plug Wire. 
21, Steel Breaker Cam. 22, Dust Cover. 24, 
Grounding Terminal. 25, Distributor Block 
Holding Spring. 116, Breaker Timing Lever. 
117, Breaker Cover. 118, Conducting Spring for 
Grounding Terminal. 119, Breaker Cover Hold¬ 
ing Spring. 










































408 The Automobile Handbook 

Bosch Magnetos. The Bosch high tension 
magneto, Fig. 182, generates its own high-ten¬ 
sion current directly in the armature winding 
and without the use of a separate coil or other 
apparatus. Apart from the cables connecting 
the magneto to the plugs, the Bosch high-ten¬ 
sion magneto requires only one grounding wire. 



Fig. 183 


The armature carries two windings. The pri¬ 
mary consists of a few layers of heavy wire and 
the secondary of a great number of layers of 
fine wire. One end of the primary winding is 
grounded on the armature core, and the live end 
is brought out to a circuit-breaking device. The 
grounded end of the secondary winding is con- 








The Automobile Handbook 


409 


nected to the live end of the primary winding 
so that one is a continuation of the other. 

During certain portions of the rotation of the 
armature the primary circuit is closed, and the 
variations in magnetic flux have their effect in 
inducing an electric current in it. When the 
current reaches a maximum, which will occur 
twice during each rotation of the armature, the 
primary circuit is broken, and the resulting ar¬ 
mature reactions produce a high-tension current 
of extreme intensity in the secondary winding. 
This current is transmitted to a distributer by 
means of which it passes to the spark plug of 
the cylinder that is in the firing position. 

The magneto interrupter, Fig. 183, is fitted 
into the end of the armature shaft which is 
taper-bored and provided with a key-way. The 
interrupter is held in position by a fastening 
screw, and may easily be removed. In replacing 
it, care should be taken that the key fits into 
the key-way and that the fastening screw is 
well tightened. 

Twice during each revolution of the armature 
the primary circuit closes and opens, this being 
effected by the interrupter lever coming in con¬ 
tact with a steel segment, which is supported 
on the interrupter housing. When the magneto 
interrupter lever is not being acted upon by the 
steel segment, the platinum points are in con¬ 
tact, thus closing the primary circuit. Then 
as the armature rotates farther and the inter¬ 
rupter lever again comes in contact with a seg- 


110 The Automobile Handbook 

ment, the platinum points (interrupter con¬ 
tacts) open and thus interrupt the primary cir¬ 
cuit. At the opening of the contact the ignition 
spark occurs instantaneously. 

The distance between the platinum points 
when the magneto interrupter lever is fully de¬ 
pressed by one of the steel segments must not 
exceed 1/32 inch. This distance may be adjusted 
by means of a long platinum screw, and should 
be in accordance with the steel gauge that is 
pivoted to the adjusting wrench. 



Fig. 184 

High and Low Tension Circuits of Bosch Magneto 


The connections of the magneto, Fig. 184, 
consist of a high-tension cable from the dis¬ 
tributor to each spark plug, and a low-tension 
cable leading to the switch. 

In order to protect the insulation of the arma¬ 
ture and of the current-carrying parts of the 























The Automobile Handbook 411 

apparatus against excessive voltage, a safety 
spark gap is arranged on the dust cover. It 
consists of a short pointed brass rod set on the 
dust cover, and a second pointed brass part sup¬ 
ported a short distance from, it in the center of 
the steatite cover of the housing. The insulated 
point is connected into the secondary circuit, 
and should there be any interference with the 
circuit normally provided through the spark 
plug the safety spark gap provides a point of 
discharge. 

If a spark is observed passing in the safety 
spark gap it is an indication that there is an 
interruption in the regular secondary circuit, 
and the cause should be at once investigated. 

A simple test for the magneto is to disconnect 
the grounding cable from grounding terminal 
- and also to disconnect the spark plug cables. 
The motor should then be cranked briskly, and 
the safety spark gap closely observed. If sparks 
are seen at this point, it is an absolute indica¬ 
tion that the magneto is in proper operating 
condition. If no sparks are observed it will be 
necessary to make sure that the primary cir¬ 
cuit is properly interrupted by the magneto in¬ 
terrupter. Holding spring must be moved side¬ 
ways, interrupter housing cover taken off, and 
it must be ascertained whether fastening screw 
is well tightened. After this it should be ob¬ 
served whether the platinum points are in con¬ 
tact when the steel cams are not acting on the 
magneto interrupter ^ lever, also whether they 


412 The Automobile Handbook 

separate the correct distance, l/25th inch, when 
the interrupter lever is resting on one of the 
steel cams. Otherwise the distance must be 
adjusted by means of the platinum screw. The 
platinum contacts .must be examined and any 
oil and dirt removed; in case the contacts are 
uneven (but only then) they must be smoothed 
with a fine flat file. If, after continued use, the 
platinum contacts are completely worn down, 
the two platinum screws must be renewed. 

The Bosch dual magneto is of the standard 
Bosch type, and produces its own sparking cur¬ 
rent, which is timed by the revolving inter¬ 
rupter. The parts of this interrupter are car¬ 
ried on a disk that is attached to the armature 
and revolves with it, the segments that serve 
as cams being supported on the interrupter 
housing. 

In addition, the magneto is provided with a 
steel cam having two projections, which is built 
into the interrupter disk. This cam acts on a 
lever that is supported on the interrupter hous¬ 
ing, the lever being so connected in the battery 
circuit that it serves as a timer to control the 
flow of battery current through the coil. 

It is obvious that the sparking current from 
the battery and from the magneto cannot be led 
to the spark plugs at the same time, and a fur¬ 
ther change from the magneto of the indepen¬ 
dent form is found in the removal of the con¬ 
ducting bar between the collecting ring and the 
distributer. The collecting ring brush is con- 


The Automobile Handbook 413 

nected to the switch and a second wire leads 
from the switch to the terminal that is centrally 
located on the distributer. 

When running on the magneto the sparking 
current that is induced thus flows to the dis¬ 
tributer by way of switch contact. When run¬ 
ning on the battery the primary circuit of the 
magneto is grounded, and there is, therefore, 
no production of sparking current by the mag¬ 
neto; it is then the sparking current from the 
coil that flows to the distributer connection. It 
will thus be seen that of the magneto and bat¬ 
tery circuits the only parts used in common are 
the distributer and the spark plugs. 

The end plate of the coil housing carries a 
handle by which the switch may be operated. 
By means of this switch either the magneto or 
the battery may be employed as the source of 
ignition current, and in its operation the entire 
coil is rotated within the housing. The inner 
side of the stationary switch plate is provided 
with spring contacts that register with contact 
plates attached to the base of the coil. 

For the purpose of starting on the spark, a 
vibrator may be cut into the coil circuit by 
pressing the button that is seen in the center of 
the end plate. Normally, this vibrator is out 
of circuit, but the pressing of the button brings 
together its platinum contacts and a vibrator 
spark of high frequency is produced. It will 
be found that the distributer on the magneto is 
then in such a position that this vibrator spark 


4 ] 4 


The Automobile Handbook 


is produced at the spark plug of the cylinder 
that is performing the power stroke; if mixture 
is present in this cylinder ignition will result 
and the engine will start. 



Fig. 185 

Bosch Dual System Wiring Diagram 


The dual system requires four connections be¬ 
tween the magneto and the switch, Fig. 185; 
two of these are high tension and consist of wire 
No. 3 by which the high-tension current from 
the njagneto is led to the switch contact, and 
wire No. 4 by which the high-tension current 
from either magneto or coil goes to the distribu¬ 
tor. Wire No. 1 is low tension, and conducts 
the battery current from the primary winding 
of the coil to the battery interrupter. Low-ten¬ 
sion wire No. 2 is the grounding wire by which 
the primary circuit of the magneto is grounded 





































The Automobile Handbook 415 

when the switch is thrown to the-“off” or to 
the battery position. Wire No. 5 leads from the 
negative terminal of the battery to the coil, and 
the positive terminal of the battery is grounded 
by wire No. 7; a second ground wire No. 6 is 
connected to the coil terminal. 



Method of Setting Armature of Bosch Magneto 

The timing of the Bosch Dual Magneto is 
identical with the standard type. The dual 
magneto is so arranged that the battery inter¬ 
rupter breaks its circuit approximately 10 de¬ 
grees later than the magneto interrupter; this 
feature gives the full timing range of the mag¬ 
neto. With the timing lever fully retarded and 
the switch on the battery position, the battery 
spark will occur after the piston has passed 









416 


The Automobile Handbook 


dead center and is moving on the power stroke. 
The possibility of a back -kick is thus eliminated. 

The magneto should be placed in position on 
the bed plate or pad provided for it, the bolts 
or straps being properly secured; the driving 
gear or coupling, however, should be loose on 
the armature shaft. The dust cover, which is 
an aluminum plate located under the arch of 
the magneto, should then be removed, and this 
is accomplished according to the design of the 
various types of magnetos. 

The engine should now be cranked until one 
of the pistons, preferably that of cylinder No. 1, 
is at the top of the compression stroke. With 
the engine in this position, the armature should 
be rotated by hand in the direction in which it 
will be driven until it is approximately in the 
position illustrated in Fig. 186. The setting of 
the armature is determined by the dimension 
marked E, Fig. 186, as follows: 

44 DU3 ’’ Model 4.11 to 14 mm. 

44 DU4’ ’ Model 4.13 to 15 mm. 

“DU6’ ’ Model 4.16 to 20 mm. 

“DU3” Model 4. 8 to 11 mm. 

4 4 DU4 ’’ Model 4.10 to 13 mm. 

44 DU6 ’ ’ Model 4.12 to 16 mm. 

With the armature held in the proper posi¬ 
tion, the gear or coupling should be secured. 
The greatest care should be exercised to prevent 
the slipping of the armature during this opera¬ 
tion. 

In the fully enclosed magneto it is unneces- 








The Automobile Handbook 417 

sary to remove either the interrupter housing 
cover or the distributer plate in order to deter¬ 
mine the setting of the instrument, or to locate 
the distributer terminal with which contact is 
made. 

The magneto having been bolted into posi¬ 
tion, the crankshaft is to be turned to bring 
one of the pistons, preferably that of cylinder 
No. 1, to the firing position for full advance. 

The armature is then rotated until the figure 
can be seen through the window in the 
face of the distributer plate. The cover of the 
oilwell on the distributer end of the magneto 
is then to be raised, and the armature is to be 
turned a few degrees in one direction or the 
other until the red mark on one of the dis¬ 
tributer gear teeth is brought to register with 
the red marks on the side of the window located 
between the two oil ducts. 

The magneto is then in time for the full ad¬ 
vance position, and the gear or coupling is to be 
secured to the armature shaft. Great care 
should be taken not to disturb the position 
either of the crankshaft or the armature shaft 
when fitting the driving member. 

Bosch Enclosed Types. In the * ‘DU” dual 
magneto, the current is led from the collector 
ring connection to the coil and back to the 
distributer terminal that is located in the cen¬ 
ter of the distributer plate. In the enclosed 
dual magneto, this central terminal is elimi¬ 
nated, and the current is led internally to the 


418 The Automobile Handbook 

distributer from a connection on the shaft end 
of the magneto. To expose this terminal, the 
shaft end bonnet should be removed, which is 
done by withdrawing the two screws in its lower 
flange, and sliding the bonnet backward. The 
terminal will then be seen to be a vulcanite post, 
with a boss that projects through a hole in the 
bonnet. In the top of this post are two vertical 
holes, in the bottom of each of which is a screw. 
These screws are to be withdrawn. The ends 
of the high-tension wires No. 3 and No. 4 lead¬ 
ing to the coil are then to be cut off square, 
and after being led through the hole in the bon¬ 
net, are to be pressed to the bottoms of the 
slanting holes in the boss. The pointed screws 
are then to be replaced in the vertical holes, and 
in being driven home they will pierce the cables 
(and their insulation) and make the required 
connections. It is essential to use a screwdriver 
of the proper size, for a tool with too large a 
blade will inevitably crack the vulcanite. Great 
care must be taken to apply the screwdriver to 
the screws vertically in order to avoid cracking 
the vulcanite by side pressure. When the con¬ 
nections are made the bonnet is to be replaced. 

Bosch Upkeep and Care. It will be noted 
that the press button on the coil is arranged to 
set in either of two positions, which are indi¬ 
cated by an arrow engraved on its surface, or 
projecting from its edge. When this button is 
in such a position that the arrow is pointing on 
the word <f run” a single contact spark will be 


The Automobile Handbook 419 

produced when the engine is cranked, or wheh 
the engine is running with the switch in the 
battery position. Under all ordinary conditions 
the button position should invariably be used. 

When the engine is chilled, however, or under 
poor mixture conditions, starting can frequently 
be facilitated by pressing down the button and 
turning it slightly to the right so that the arrow 
is pointing to the word “start .’ 9 This will lock 
the vibrator in circuit, and a shower of vibrator 
sparks will be produced in place of the single 
contact spark. 

The platinum points of the magneto inter¬ 
rupter should be kept clean and smooth and so 
adjusted that they are open about 1/64 inch, 
or the thickness of the gauge attached to the ad¬ 
justing wrench, when the magneto interrupter 
lever is wide open on one of the rollers or seg¬ 
ments. It should not be necessary to dean or 
readjust these points oftener than once a season, 
and it is not advisable to readjust them until 
their condition and the missing of the engine 
show it to be absolutely necessary. 

Each coil is stamped with the voltage of the 
battery current for which it is wound, and if 
this voltage is not exceeded the platinum con¬ 
tacts of the battery interrupter will not require 
attention for long periods. When this battery 
interrupter lever is being operated by the roll¬ 
ers or segments, the platinum points should be 
slightly wider open than the contact points of 
the magneto interrupter—the proper distance 
being about 1/50 inch. 


420 The Automobile Handbook 

If the-magneto is at fault, all the cables ana 
terminals should be examined for improper con¬ 
nections. The coil and battery system may then 
be disconnected by removing the wires from 
terminals Nos. 3 and 4 of the magneto, and with 
a short piece of wire magneto terminal No. 3 
may be connected directly with magneto ter¬ 
minal No. 4. This will conduct the high-tension 
current induced in the magneto direct to the 
distributer. The grounding wire should then 
be disconnected from terminal No. 2 of the 
magneto. With this arrangement it should be 
possible to start the engine on the magneto, and 
it will be necessary to follow this plan should 
any accident happen to the coil. 

To ascertain if the magneto is generating cur¬ 
rent, the grounding wire should be disconnected 
from terminal No. 2 on the magneto, and the 
high-tension wire should be disconnected from 
the collecting ring terminal No. 3. If the engine 
is then cranked briskly a spark should appear 
at the safety spark gap that is located under 
the arch of the magnets on the dust cover, 
provided the magneto is in proper condition. 
The grounding wire should then be reconnected 
to terminal No. 2, and the engine cranked. If 
no spark appears at the safety spark gap, the 
trouble may be determined as a leakage of the 
primary magneto current to ground by chafed 
insulation, incorrect connections, or an injury 
to the switch parts. 

The coil may be tested by disconnecting wire 


The Automobile Handbook 421 

No. 4 from the magneto and throwing the switch 
to the battery position, operating the press but¬ 
ton with terminal No. 4 3/16 inch from the 
metal of the engine. If the coil is in good con¬ 
dition, a brilliant spark should be observed. If 
the spark does not appear the test should be re¬ 
peated with wire No. 3 disconnected. If the 
fault persists the coil body may be removed 
from the housing by withdrawing the holding 
screw that is located close to the supporting 
flange; the switch should then be unlocked and 
the end plate given a quarter revolution. This 
will release the bayonet lock and the coil body 
may then be withdrawn to permit the inspection 
of the switch contacts both of the coil and of 
the stationary switch plate. It may be that the 
spring contacts are bent or otherwise in bad 
condition. The withdrawing of the coil body 
and its handling should be performed with ex¬ 
treme care. No work should be done on the coil 
in the way of withdrawing screws, etc., and if 
the inspection does not disclose the fault the 
coil should be returned to its housing and the 
whole returned to the makers or to one of their 
branches. 

Bosch “NTJ” Magneto. Like other Bosch 
high-tension magnetos, the type “NU4,” Fig. 
187, generates its own high-tension current di¬ 
rectly in the magneto armature (the rotating 
member of the magneto) without the aid of a 
separate step-up coil, and has its timer and 
distributer integral. The distinct gear-driven 


422 The Automobile Handbook 

distributor common to othei; types has been 
omitted in the “NU4” magneto, and in its stead 
is a double slipring combining the functions of 
current collector and distributor. 

The armature winding is composed of two 
sections: one, primary, or low tension, consist¬ 
ing of a few layers of comparatively heavy 
wire, and the other, secondary, or high tension, 
consisting of many layers of fine wire. 



ifH 

j - w/T/9\- 

J 17 J£y\\ 

%■ | ^ 

T 
~\ k 

_ r 

! 

1 - q - 

-p- 



Bosch High Tension Magneto, Model “NU” 

The beginning of the primary winding is in 
metallic contact with the armature core, and 
the other, or live, end is connected by means of 
the interrupter fastening screw to the insulated 
contact block supporting the long platinum 
screw on the magneto interrupter. The inter¬ 
rupter lever, carrying a short platinum screw, is 
mounted on the interrupter disc which, in turn, 
is electrically connected to the armature core. 
The primary circuit is completed whenever the 










































The Automobile Handbook 


423 


two platinum interrupter screws are in contact 
and interrupted whenever these screws are sepa¬ 
rated. The separation of the platinum screws is 
controlled by the action of the interrupter lever 
as it bears against the two steel segments se¬ 
cured to the inner surface of the interrupter 
housing. The high-tension current is generated 
in the secondary winding only when there is an 
interruption of the primary circuit, the spark 
being produced at the instant the platinum in¬ 
terrupter screws separate. 

The secondary winding is insulated from the 
primary, and the two ends of the secondary are 
connected to two metal segments in the slipring 
mounted on the armature, just inside the driv¬ 
ing shaft end plate of the magneto. The slip¬ 
ring has two grooves, each containing one of 
the two metal segments. These segments are set 
diametrically opposite on the armature shaft, 
that is, 180 degrees apart, and insulated from 
each other, as well as from the armature core 
and magneto frame. 

The four slipring brushes which are part of 
the secondary circuit are supported by two 
double brush holders, one on each side of the 
driving shaft end plate, each holder carrying 
two brushes so arranged that each brush bears 
against the slipring in a separate groove. Upon 
rotation of the armature, the metal segment in 
one slipring groove makes contact with a brush 
on one side of the magneto at the same instant 
that the metal segment in the other slipring 


424 The Automobile Handbook 

groove comes into contact with a brush on the 
opposite side of the magneto. The marks 1 and 
2 appearing in white on both brush holders in¬ 
dicate pairs of brushes receiving simultaneous 
contact, those marked 1 constituting one pair, 
and those marked 2 the other. 

A spark is caused at two plugs simultane¬ 
ously. It is important to note that as two of 
the four slipring brushes receive contact simul¬ 
taneously and each is connected by cable to the 
spark plug in one of the cylinders, the secondary 
circuit always includes two plugs, and the spark 
occurs in two cylinders simultaneously. 

After removing one of the brush holders to 
permit observation of the slipring, the armature 
shaft is rotated in the direction in which it is 
to be driven, until the beginning of the metal 
slipring segment is visible in the slipring groove 
corresponding to Fig. 1 of the brush holder 
which has been removed. With that done, the 
cover of the magneto interrupter housing is to 
be removed to expose the interrupter. The 
armature shaft should then be further rotated 
until the platinum interrupter screws are just 
about to separate, which occurs when the inter¬ 
rupter lever begins to bear against one of the 
steel segments of the interrupter housing. 

The armature should be held in that position 
while the magneto drive is connected to the 
engine, due care being taken that the piston of 
No. 1 cylinder is still exactly on top dead center 
of the compression stroke. 


The Automobile Handbook 425 

After the brush holder and interrupter hous¬ 
ing cover have been replaced the installation is 
completed by connecting the cable of one of the 
brushes, marked 1, with cylinder No. 1, Fig. 188, 
and the other with cylinder No. 4; the remain¬ 
ing two cables, leading from the brushes, marked 
2, must be connected with cylinders Nos. 2 
and 3. 



Fig. 188 

Wiring Connections for Bosch Magneto, Model 
“NU” 


Dixie Magneto. The Mason principle on 
which the Dixie magneto operates is shown in 
Fig. 189. The magnet has two rotating polar 
extremities, N S, which are always of the same 
polarity, never reversing. These poles are in 
practical contact with the inner cheeks of the 
permanent magnet M, all air gaps being elimi¬ 
nated. Together with the U-shaped magnet, 
they form a magne't with rotating ends. 















































426 


The Automobile Handbook, 


At right angles to the rotating poles is a field 
consisting of pole pieces F and G, Fig. 190, 
carrying across their top the core C and the 
windings W. When N is opposite G, the mag¬ 
netism flows from pole N on the magnet to G 
and through the core C to F. 



Fig. 189 

Dixie Magneto Principle 
In Fig. 191 the pole N has moved over to F 
and the direction of the flow of magnetism is 
reversed; it now flowing from F through C to 
G. The rotating poles do not reverse their 
polarity at any time, consequently the lag due 
to the magnetic reluctance in this part is elimi¬ 
nated. 

The magneto has a rotating element consist¬ 
ing of two pieces of cast iron with a piece of 
brass between them, but no armature of the 
usual form, the revolving generating element 
being shown in Fig. 192. The pieces N S are 
separated by the brass block B and correspond 
to the pieces N S in Figs. 189,190 and 191. The 
generating windings are carried on a small coil 
placed across the upwardly projecting ends of. 
two pole pieces. 













The Automobile Handbook 427 

The core of the coil A, Fig. 193, is stationary) 
and the inner end G of the primary winding 
P is grounded on the core. Q indicates the 
metal frame of the machine, which is put to- 



Fig. 190 Fig. 191 

Dixie Magneto Action Reversal of Magnetism 

Through Dixie Magneto 

gether with screws. The condenser R is located 
immediately above the coil and is readily re- 



Rotating Element in Dixie Magneto 


movable. The terminal D is a screw on the 
head of the coil and the wire Z connects di¬ 
rectly to the contact Y of the breaker. The 
breaker contacts are stationary and do not re¬ 
volve as in the armature type. 





























428 The Automobile Handbook 

Fig. 194 shows the high tension circuit. Here 
the end C of the high tension winding goes to 
a metal plate D carried on the upper side A of 
the coil. Against D bears a connection F, which 
is practically one piece with the traveling con¬ 
tact J, which connects to the spark plug seg¬ 
ment L, the circuit being completed through the 
spark plug, engine frame and frame of magneto 
in the usual manner without brush G. 



Fig. 193 

Low Tension Primary Circuit of Dixie Magneto 

The proper distance between the platinum 
points when separated should not exceed 1/50 of 
an inch, and a gauge of the proper size is at¬ 
tached to the screwdriver furnished with the 
Dixie. 

The platinum contacts should be kept clean 
and properly adjusted. Should the contacts be¬ 
come pitted, a fine file should be used to smooth 
them in order to permit them to come into per¬ 
fect contact. The distributor block should be 













The Automobile Handbook 


429 


removed occasionally and inspected for an ac¬ 
cumulation of carbon dust. The inside of the 
distributor should then be wiped dry with a 
clean cloth. When replacing the block, care 
must be taken in pushing the carbon brush into 
the socket. The magneto should not be tested 
unless it is completely assembled, that is, with 
the breaker box, distributor cover and wires in 
position. 



Fig. 194 

High Tension Circuit of Dixie Magneto 

In order to obtain the most efficient results 
with the Dixie magneto the normal setting of 
the spark plug points should not exceed .025 of 
an inch and it is advisable to have the gap just 
right before a spark plug is inserted into the 
cylinder. The spark plug electrodes may be 
easily set by means of the gauge attached to the 
screwdriver furnished with the magneto. 

















430 


The Automobile Handbook 


Eisemann Magnetos. Recent models of Eise- 
mann magnetos have been designated as the G4 
type. The breaker of the first G4 instruments 
is shown in Figure 195. Its cam is stationary 
except for the movement in advance and retard, 
while the breaker arm and contact carrying parts 
are carried by the armature shaft and revolve 
around the cam. The moving contact point is 



carried at the end of a flat contact spring. Back 
of the contact spring is a pressure spring which 
serves to hold the contacts closed when not being 
acted upon by the cam. 

A later breaker mechanism is shown in Figure 
196. This breaker is similar to the design used 












The Automobile Handbook 


431 


on some of the older models and might be taken 
as typical of many true high tension magnetos. 
The cams are stationary in the circumference of 
the housing, while the contact arm and fixed con¬ 
tact carrying parts are attached to the end of 



the armature shaft and revolve with it. The 
breaker housing and cam are rotated to secure 
advance and retard. 

The armatures of these magnetos are of the 
conventional shuttle type. The distributors are 
of the wipe contact type having a metal seg¬ 
ment set into the rotor, this segment revolving 






432 The Automobile Handbook 

« 

past a series of carbon brushes set into the cover. 
A safety spark gap is provided by means of one 
or two small brass screws which pass through 
the armature housing and have their inner ends 
extending to within about % of an inch of the 
collector ring on the armature shaft. 



Some of the coil units include a device, shown 
in Figure 197, for starting on the spark. The 
mechanism consists of a three tooth ratchet en- 








































The Automobile Handbook 


433 


gaging a roller A on a lever B. This lever car¬ 
ries a double face contact. This contact makes 
and breaks the primary circuit by making con¬ 
tact alternately with the fixed points C and D. 
This action results in a stream of sparks at the 
spark plug in the cylinder then ready to fire and 
if there is a combustible mixture in the cylinder 
the engine will start. 



Pole Piece Construction in Eisemann Magneto 

The Eisemann dual system consists of a direct 
high-tension magneto and a combined trans¬ 
former coil and switch. The transformer proper 
is used only in connection with the battery; 
the switch is used in common by both battery 
and magneto systems. The magneto is prac¬ 
tically the same as the single ignition instru¬ 
ment. Separate windings and contact breakers 
are used for battery or magneto current. On 
the other hand, parts that are not subject to 
accident, or rapid wear, are used in common. 


/ 


































434 


The Automobile Handbook 


A distinctive feature is that the pole pieces 
are of a certain shape, Fig. 198, whereby the 
most extended portion thereof is approximately 
opposite the theoretical axis of the winding 
upon armature core. This construction results 
in the flow of the magnetic lines of force being 
drawn from the extremities of the pole pieces 
towards the center of the core; a large volume 
of the magnetic line of force is thus forced 
through the winding. 



Breaker of Eisemann Magneto 

The make-and-break mechanism, Fig. 199, 
consists of a bronze plate on the back of which, 
and cast in one piece with it, is a cone, fitting 
into the armature shaft, which is bored out 
and provided with a key-way. It moves inside 
of the timing lever and is fastened to the arma- 



















The Automobile Handbook 


435 


ture by means of the screw. If this screw is 
extracted the whole mechanism can be removed. 

The primary current is led from the winding 
through the armature shaft to the contact screw 
by the insulated screw, which also serves to hold 
the mechanism to the armature shaft as already 
described. When the armature reaches the cor¬ 
rect position, a lever is lifted by two steel cams 
fastened to the magneto body; the primary cir¬ 
cuit is broken and the current is induced in the 
secondary winding. The beginning of the sec¬ 
ondary winding is connected with the end of the 
primary winding, and the other end, through 
several mediums, finally delivers the spark in 
the cylinder. 

In addition to this the magneto is also fitted 
with the battery circuit breaker, which is mount¬ 
ed at the back of the magneto breaker. It con¬ 
sists of a steel cam, having two projections 
which actuate a steel lever mounted into the 
breaker housing. 

A condenser is built in between the T-shaped 
end of the armature and the bearing. This pre¬ 
vents a spark occurring at the platinum con¬ 
tacts with the consequent pitting and burning, 
when the contact breaker opens, and it also in¬ 
creases the intensity of the spark at the plugs. 

The coil consists of a non-vibrating transform¬ 
er and a switch, which is used in common to 
put either the battery or magneto ignition into 
operation. It is cylindrical in shape, compact, 


431 ) 


The Automobile Handbook 


and is placed through the dashboard. The end 
which projects through on the same side as the 
motor has terminal connections for the cables. 
The other end, facing the operator, contains the 
switch and the starting mechanism. The trans¬ 
former proper is used only in conjunction with 
the battery. 

As the spark occurs when the primary circuit 
is broken by the opening of the platinum con¬ 
tacts, it is necessary that the magneto will be so 
timed that at full retard the platinum contacts 
will open when the piston has reached its highest 
point on the firing stroke. To arrive at this, turn 
motor by hand until piston of No. 1 cylinder 
is on the dead center (firing point). Place the 
timing lever of the magneto in fully retarded 
position, then turn armature of magneto until 
No. 1 appears at the glass dial of the distributer 
plate, and make sure that the platinum contacts 
of the magneto are just opening. Fix the driv¬ 
ing medium in this position. 

If no window is seen, turn motor by hand 
until piston of No. 1 cylinder is on dead center 
(firing point), remove the distributer plate from 
the magneto and turn the drive shaft of the 
armature until the setting mark on the distribu¬ 
ter disc is in line with the setting screw above 
the distributer. (For magneto rotating clock¬ 
wise use setting mark R, and for counter clock¬ 
wise use mark L.) With the armature in this 
position the platinum contacts are just opening 
and the metal segment of the distributer disc 


The Automobile Handbook 437 

is in connection *with carbon brush for No. 1 
cylinder. The driving medium must now be 
fixed to the armature axle without disturbing 
the position of the latter, and the cables con¬ 
nected to the spark plugs. 

If a spark plug cable becomes disconnected or 
broken, or should the gap in the spark plug be 
too great, then the secondary current has no 
path open to it, and endeavoring to find a 
ground will sometimes puncture the insulation 
of the armature of the coil. To obviate this, a 
so-called safety spark gap is placed on the top 
of the armature dust cover. It consists of pro¬ 
jections of brass with a gap between them. One 
of these is an integral part of the dust cover, 
and therefore forms a ground. The other brass 
part is connected with the terminal H M and 
the secondary current will jump across the in¬ 
tervening gap above mentioned, thus protecting 
the armature secondary winding and the high 
tension insulations. 

In the coil, this safety gap is placed at one 
end of the core, and hence is not visible. It 
consists of a pointed brass finger, attached to 
one end of the secondary, and pointing towards 
the iron core of the coil. 

The contact points may be cleaned with gaso¬ 
line until the contact surface appears quite 
white, or use a fine file, but very carefully, so 
that the surfaces remain square to each other. 
The gap at the contact points should not amount 
to more than 1/64 inch and, as the contacts 


438 The Automobile Handbook 

wear away in time, they must* be regulated now 
and then by giving the screw a forward turn, 
or eventually by renewing. When this platinum 
tipped screw is adjusted, care must be taken 
that the lock-nut is securely tightened in place. 
By loosening the center screw, the whole inter¬ 
rupting mechanism may be taken out, so that 
the replacement of the platinum contacts with¬ 
out removing the apparatus can be easily done 
at any time. The fixing screw of the make-and- 
break is held fast by a lock spring, so that it 
is impossible for this screw to loosen. When it 
is desired to remove this screw, the lock spring 
must first be removed by turning it over the 
head of the screw. Do not forget to put the 
spring in the original position after having fixed 
the make-and-break to the armature. 



Magneto 

The Eisemann automatic advance, Fig. 200, is 
accomplished by the action of centrifugal force 
on a pair of weights A attached at one end to a 
sleeve B, through which runs the shaft C of the 
magneto, and hinged at the other end to the 
armature. 


















The Automobile Handbook 439 

Along the armature shaft arm run two spiral 
ridges which engage with similarly shaped 
splines in the sleeve. When the armature is 
rotated the weights begin to spread and exert a 
longitudinal pull on the sleeve which in turning 
changes the position of the armature with refer¬ 
ence to the pole pieces. In this way the moment 
of greatest current is advanced or retarded, and 
with it the break in the primary circuit, for the 
segments which lift the circuit breaker and 
cause the break in the primary circuit are fixed 
in the correct position and thus the break can 
only occur at the moment when the current in 
the winding is strongest. On magnetos without 
this advance it is the segments which are moved 
forward or back, as the case may be. As there 
is only one actually correct position for the seg¬ 
ments, every degree away from this weakens 
the spark. 

The spreading of the weights rotates the arma¬ 
ture forward, and advances the spark and the 
resumption, either total or in part, of their 
original position close to the shaft, retards it by 
rotating the armature backward. 

As the timing is accomplished by changing 
the relative positions of armature and motor 
and not those of the segments in the timing level 
which cause the breaking of the circuit, the 
spark is always bound to occur at the moment 
of greatest current and the apparatus thus 
given as strong a spark at retard as when fully 
advanced. 


440 


The Automobile Handbook 


As the speed becomes slower a spring D 
brings the weights together again, so that by 
the time the motor has come to rest the magneto 
is fully retarded 

In the rear end of the governor housing there 
is a transverse slot into which fits a key, fur- 



Fig. 201 

Magneto Used on the Ford Cars 
nished with each magneto. When this key is 
shoved in as far as it cam go the armature is 
fixed in the position where the platinum con¬ 
tacts begin to open. v The coupling may bo 
screwed up with the assurance that the magneto 
is correctly set and without danger of damag¬ 
ing the armature. 















































The Automobile Handbook 


441 


Ford Magneto. The Ford magneto, .Fig. 
201, is o*f a peculiar design, it being constructed 
as an integral part of the flywheel, in which A 
is the support for the magneto coils; BBB, mag¬ 
neto coils; CC, permanent horseshoe magnets; 
i)D, the flywheel; E, planetary pinions; F, low 
speed brake band; G, reverse brake band; II, 
disc-clutch for high speed; I, transmission 



Fig. 203 


Fig. 202 


Details of Ford Magneto 


brake; J, clutch rocker shaft, and K, high speed 
clutch spring. The permanent magnets, which 
are U-shaped, are bolted to the forward face of 
the flywheel, as shown in Fig. 202. Close in front 
of their outer ends is a series of insulated coils 
mounted in a circle of practically full flywheel 
diameter, with their axes parallel with that of 
the crankshaft. They are supported upon a 
stationary spider, as shown in Fig. 203. As the 
flywheel revolves, this magnet and coil com¬ 
bination, which is similar to that used on some 



442 


The Automobile Handbook 


types of alternating current generators, pro¬ 
duces a current which is used through a four- 
unit current timer to cause the ignition spark. 
The magneto is of the inductor type, the arma¬ 
ture coils being stationary, and the field mag¬ 
nets moved past them. Sixteen separate field 
magnets are used, made of vanadium-tungsten 
steel. They are substantially horseshoe shape, 
being secured to the side of the flywheel as illus¬ 
trated in Fi£. 203. They are held in place by 
screws at their middle, and by clamps near their 
poles, all screws used for fastening them being 
securely locked in place by wire locks. 

The magnets are so arranged that like poles 
are adjacent to each other, forming a six¬ 
teen pole field magnet crown. Instead of being 
placed close against the flywheel, these mag¬ 
nets are clamped against a ring of non-magnetic 
material (brass for instance), in order to re¬ 
duce leakage of magnetism through the fly¬ 
wheel rim. At their middle these magnets are 
fastened directly to the flywheel, as at this point 
they are neutral, and there can be no leakage. 
A series of sixteen armature coils is carried on 
a coil supporting ring slightly in front of the 
flywheel, as shown in Fig. 202. These coils are 
wound with heavily insulated magnet wire, and 
are so grouped around the supporting ring that 
the winding of adjacent coils is in different di¬ 
rections, one being wound clockwise, and the 
next one counter clockwise. The coils are con¬ 
nected in series, the terminals being brought 


The Automobile Handbook 44 tv 

out near the top of the casing. As the poles 
of the magnets are located opposite and very 
close to the coils, the magnetic circuits are com¬ 
pleted by the cores of these coils and the coil 
support. There are evidently sixteen electrical 
impulses produced during the revolution of the 
crankshaft and flywheel, although only two im¬ 
pulses are required for the ignition of the mo¬ 
tor, one per stroke. However, as the armature 
circuit is closed only when a spark is wanted, 
a current only flows at that period, and there 
is no loss from the other impulses. 

Mea Magneto. The most noticeable differ¬ 
ence between the Mea magneto and other stand¬ 
ard forms is that the magnets are bell-shaped 
and are placed horizontally and with their axes 
in line with the armature shaft. This is a dis¬ 
tinct variation from the customary horseshoe 
magnets placed at right angles. This makes 
possible the simultaneous movement of the mag¬ 
nets and breaker instead of the advance and 
retard of the breaker alone. 

It will be seen that, as a result of this con¬ 
struction, the relative position of armature and 
field at the moment of sparking is absolutely 
maintained, and the same quality of spark is 
therefore produced, no matter what the timing 
may be. 

Fig. 204 shows a longitudinal section of a 
four-cylinder instrument. In the bell-shaped 


444 The Automobile Handbook 

magnet 100, having the poles on a horizontal 
line near the driven end of the magneto, rotates 
armature 1 in ball bearings 17 and 18. The 
armature consists mainly of an I-shaped iron 
core, mounted on a spindle, and wound with a 
heavy primary winding of a few turns and a 
light secondary winding of many turns. On 
this armature are also mounted the condenser 
12, the collector ring 4, and the low-tension 



Fig. 204 
Mea Magneto 

breaker 26-39. The latter is built up of a disc 
27, which carries the short platinum contact 33; 
the other contact point 34 is adjustable and 
supported by a spring 20, which in turn is fas¬ 
tened to the insulated plate 28 mounted on disc 
27. The breaker is actuated by the fibre roller 






















The Automobile Handbook ^45 

31 in connection with cam disc 40, which is 
provided with two cams and located inside the 
breaker, being fastened to the field structure. 
In revolving with the armature the roller 
presses against the spring supported part of the 
breaker whenever it rolls over the two cams and 
in this manner opens the breaker twice every 
revolution. Inspection of the breaker points is 
made possible by means of an opening in the 
side of the breaker box, provided at the point 
of the circumference at which the breaker opens. 
The box is closed by a cover 74, supporting at 
its center the carbon holder 47, by means of 
which the carbon 46 is pressed against screw 24. 
This latter screw connects with one end of the 
low tension winding, while the other end is 
connected to the core of the armature. It will, 
therefore, be seen that the breaker ordinarily 
short-circuits the low tension winding and that 
this short-circuit is broken only when the break¬ 
er opens; it will also be apparent that when 
the screw 24 is grounded through terminal 50 
and the low-tension switch to which it is con¬ 
nected, the low-tension winding remains perma¬ 
nently short-circuited, so that the magneto will 
not spark. The entire breaker can be removed 
by loosening screw 24. 

The high tension current is collected from col¬ 
lector ring 4 by means of brush 77 and brush 
holder 76, which are supported by a removable 
cover 91, which also supports the low tension 
grounding brush 78 provided to relieve the ball 


446 The Automobile Handbook 

bearing of all current which might be injurious. 
Cover 91 also carries the safety cap 89, which 
protects the armature from excessive voltages in 
case the magneto becomes disconnected from the 
spark plugs. 

The distributer consists of the stationary part 
70 and the rotating part 66, which is driven 
from the armature shaft through steel and 
bronze gears 7 and 72. The current reaches this 
distributer from carbon 77 through bridge 84 
and carbon 69. It is conducted to brushes 68 
placed at right angles to each other and making 
contact alternately with four contact plates em¬ 
bedded in part 70. These plates are connected 
to contact holes in the top of the distributer, 
into which the terminals of cables leading to the 
different cylinders are placed. 

In the front plate of the magneto is provided 
a small window, behind which appear numbers 
engraved on the distributer gear which corre¬ 
spond to the numbers marked on the top of the 
distributer. This indicator allows a setting or 
resetting after taking out, without the necessity 
of opening up the magneto to find out where 
the distributer makes contact. Numbers on in¬ 
dicator and distributer show the sequence of 
sparks, not the numbers of cylinders which the 
magneto is firing, as the sequence of firing 
varies with different motors. 

The variation of timing is effected by turn¬ 
ing the magneto proper in the stationary base 
which is accomplished through the spark lever 


The Automobile Handbook 447 

connections attached to one of the side lugs. 
The spark is advanced by turning the magneto 
in the direction of the rotation of the armature. 

If the magneto is defective, the trouble will 
usually be located in the breaker. The plati¬ 
num contacts burn off in time and a readjust¬ 
ment becomes necessary, although this should be 
the case only at very long intervals. The ad¬ 
justment should be such that the breaker begins 
to open with the armature in the position of 
greatest current flow, and that the distance be¬ 
tween contact points when fully open is about 
1/64 inch or slightly more. The small gauge 
attached to the magneto wrench may be used 
for checking this adjustment. The small lock 
nut of the contact screw must be tightened se¬ 
curely after each readjustment of the contacts. 

In addition any oil or dirt reaching the con¬ 
tact points will in time form a fine film which 
prevents perfect short-circuit of the low-tension 
winding. If the condition of these points is 
very bad, or if a complete inspection of the 
breaker is desired, the latter should be removed 
from the breaker box. This can readily be done 
by loosening the long center screw holding the 
breaker to the armature, and screwing it into 
the small tapped hole provided in the breaker, 
so that it may be used as a handle in lifting 
the breaker out. The cleaning of the points 
should be done with a fine crocus paper, or if 
necessary, with a 'very fine file, after which a 


448 


The Automobile Handbook 


piece of very fine cloth should be passed through 
between the points so as to remove all sand or 
filings. Special care must be taken not to round 
off the edges of the contact points; the satisfac¬ 
tory operation of a magneto depends largely 
upon the perfect contact at this point, and the 
whole surface of the contacts should therefore 
touch. 

Remy Magnetos. The first models of Remy 
magnetos were constructed on the inductor prin¬ 
ciple which may be understood by reference to 
Figure 205. The magnets M are of the horse¬ 
shoe type and have their positive and negative 
poles on opposite sides of the rotating inductor 
A which is made of laminated iron and carried 
on the driving shaft S. The inductor consists 
of a central portion having extensions at each 
end, the extension at one end pointing one way 
while the other extension points in the opposite 
direction. Around the center of the inductor is 
wound a stationary primary coil C. 

With the parts as shown in position 1 the flow 
of magnetism from the positive to the negative 
magnet pole passes downward through the coil. 
At the end of a quarter turn, position 2, the 
extensions of the inductor are midway between 
the magnet poles and the flow of magnetism is 
ready to reverse its direction. In position 3 the 
flow has reversed and a powerful current im¬ 
pulse has been induced in the coil winding. 
Continued rotation of the shaft causes a suc¬ 
cession of impulses in the coil and these cur- 


* The Automobile Handbook 


449 


rent waves are used, as in the revolving arma¬ 
ture magneto, for the production of a secondary 
current in a separate coil. 

The breaker mechanism used with one of the 
Remy inductor models is shown in Figure 206. 
The contact gap of this instrument may be ad¬ 
justed from outside of the housing. 



M 


n 


:*c; 


u 


M 




Fig. 205 

The inductor principle is not used in latei 
models of the Remy magneto, this feature being 
replaced by an armature of the shuttle type 
with a single low-tension winding. A sepa¬ 
rately mounted transformer coil is used with 
these instruments, this coil carrying a switch 
that allows use of the current from the magneto 
armature or from a set of dry cells or storage 
















































450 The Automobile Handbook 

battery, the current, from whichever source, 
passing though the same breaker, coil, distribu¬ 
tor and plugs. 

The breaker of the new models is composed of 
a steel cam mounted upon and turning with the 
armature shaft and which strikes against a 
contact piece in a pivoted arm that carries one 
of the contacts of the breaker. Except for the 



Breaker Mechanism of Remy “RD” Magneto 

movement required in altering the time of the 
spark, the contacts and the pivoted arm remain 
stationary, the cam being the only revolving 
part of the breaker mechanism. The condenser 
that is attached between the breaker contacts is 
carried in a housing that is mounted above the 
magneto armature and between the magnet legs. 




Fig. 207 

Wiring of Remy Magnetos "P” and “32 


The Automobile Handbook 451 

A device, known as a timing button, is incor¬ 
porated on the Models “P,” “30,” “31” and 




“32” Remy magnetos, for the purpose of tim¬ 
ing the magneto in connection with the engine. 




































452 The Automobile Handbook 

To set the magneto turn the engine crankshaft 
until the piston of No. 1 cylinder is at top cen- 


■a#* 
jnBt 



ter after the compression stroke. Press in on 
the timing button at the top of the distributor 


Fig. 208 

Wiring of Remy Magnetos “30” and “31’ 



















































The Automobile Handbook 


453 


and turn the magneto shaft until the timing but¬ 
ton is felt to drop into the recess on the dis¬ 
tributer gear. With the magneto in this posi¬ 
tion, make the coupling with the engine without 
paying any attention to the position of the 
breaker cam. The location of the distributer 
terminal for the plug in No. 1 cylinder is deter¬ 
mined by the direction of rotation of the mag¬ 
neto. If the magneto runs clockwise, No. 1 ter¬ 
minal is at the lower left hand corner of the dis¬ 
tributer, while for anti-clockwise drive No. 1 
terminal is at the lower right hand corner. The 
wiring for the Models “P” and “32” is shown 
in Fig. 207, while the connections for Models 
“30” and “31” are shown in Fig. 208. 

Simms Magneto. The armature is of the true 
high-tension type, on which is wound both the 
low-tension primary and high-tension secondary 
windings, connected, in series. The magneto 
generates a high-tension current directly in the 
armature, and does not use an exterior coil or 
other device to step-up or transform the cur¬ 
rent. 

A safety spark gap is provided to prevent 
damage to the magneto, in the event of one or 
more'of the high-tension cables becoming dis¬ 
connected from the spark plugs. This gap is 
so located that its action may be readily ob¬ 
served for the purpose of locating the cause of 
possible misfiring. 

The model “SUD” consists of a dual system 
in which is provided a small non-vibrating coil 


454 The Automobile Handbook 

which can be either attached to the frame or 
dash of car, as the coil is unaffected by either 
moisture or heat. 

The switch operating the battery circuit is in 
connection with the starting switch and when 
the starting pedal is depressed (thereby throw¬ 
ing the starting motor into operation) the cur¬ 
rent flows through the switch coil and magneto. 



Magnets and Extended Pole Pieces of Simms 
Magneto 

As soon as the engine starts, or the starting 
pedal is released, the circuit is automatically 
disconnected, and the engine runs on the mag¬ 
neto. One of the principal features of the 
Simms magneto is the extended pole shoe, shown 
in Fig. 209. 

















The Automobile Handbook 


455 


To time the magneto to engine: Turn the 
engine over by the starting crank until No. 1 
piston reaches top dead center on compression 
or firing stroke. Remove the dust cover, or if 
a dual magneto, the commutator, and turn the 
armature shaft until the figure 1 appears in the 
*‘sight-hole” of distributor, Fig. 210. This 
shows that that distributor brush is in contact 



with distributor post 1. Retard the contact 
breaker and move the armature, either to the 
right or left, as occasion requires, until the plat¬ 
inum points just break, or, in other words, just 
separate. With the magneto in this position 
couple it to the engine (to dead center on com- 












456 


The Automobile Handbook 


pression stroke), and connect the remaining ter¬ 
minals up in the'proper firing order of the 
engine. 

For timing the model S U D, proceed as 
above. The above instructions relative to en¬ 
gine position apply also in this instance. The 
only change is as follows: 

For locating the position of the carbon brush 
on No. 1 distributer segment, remove the dis¬ 
tributer, which is held in place by means of two 
spring clips, and turn the armature shaft until 
the distributer brush is brought into position, 
namely, opposite No. 1 segment. 

If the magneto is not firing, try the follow¬ 
ing test. While the motor is running, discon¬ 
nect one of the high tension cables from spark 
plug, being careful not to touch the metal ter¬ 
minal, and hold the cable with the terminal 
close, about V 8 " to 3/16", to any part of the 
motor. This will show the strength of the spark 
and each cable may be tested in turn. If the 
magneto is not delivering a good spark, examine 
the contact breaker. The break or gap between 
the platinum points, when open due to the cam 
action, should correspond to the thickness of the 
gauge furnished, which is approximately .015. 

Splitdorf Magneto. The system used in old¬ 
er models is that having an armature with but 
one winding, and giving a current of compara¬ 
tively low tension. The current is discharged 
through a transformer having a low and a high- 
tension winding somewhat similar to regular 


The Automobile Handbook 


457 


spark coil. This steps the current up to a volt¬ 
age sufficiently high to enable it to jump the 
necessary gap between the points of a spark 
plug in the compressed mixture in the cylinder 
of the motor. 

The plain H, or shuttle, armature is mounted 
between two annular ball bearings, Fig. 211. 
One end of the shaft is the driving end and the 
other is equipped with the breaker cam and the 



Fig. 211 


Section Through Splitdorf Magneto 

insulation plug which delivers the current gen¬ 
erated in the armature to the collector brushes 
from which it is transmitted to the transformer 
connection. 

From A, Fig. 212, the armature current goes 
through the primary of the transformer, return¬ 
ing through the binding post No. 2 to the con¬ 
tact screw bracket on the breaker box. No. 3 is 
a common ground connection for both the mag¬ 
neto and transformer. The circuit being broken 





















458 The Automobile Handbook 

at the proper moment, a very high voltage cur¬ 
rent is induced in the secondary winding of the 
transformer, and being delivered to the heavily 
insulated cable D, is conducted to the central 
brush of the distributor, whence it is delivered 
to the spark plugs in the different cylinders in 
correct sequence. 



Wiring of Model “S M Splitdorf Magneto 

In addition to using the current from the 
magneto, the transformer may be used as a 
spark coil by using the breaker mechanism of 
the magneto in the circuit to interrupt a cur¬ 
rent from the battery, which can be switched 
in for starting purposes or for an emergency. 
The distributor is used to deliver the current 
thus generated to the spark plugs. This gives a 
dual system with one set of spark pings, and 
the movement of the switch controls both sys¬ 
tems. Fig. 213. 






























The Automobile Handbook 


459 


A later development is the new standard 
“T S” type of transformer, Fig. 214, which 
has practically superseded all other types, par- 



Coii 

ticularly as it does away with the separate 
switch and still leaves the dash free. Both leads 
from the battery must run direct to transformer. 


To Plugs 



Wiring of Splitdorf Magneto With Tubular Coil 
















































460 The Automobile Handbook 

After securing the magneto to the prepared 
base on the motor, crank it until cylinder No. 

1 is exactly on its firing center (i. e., the point 
of greatest compression. The motor must re¬ 
main in this position until the balance of the 
work is finished. 

Retard the spark advance mechanism at the 
steering wheel to its limit and connect it to the 
spark advance lever on the breaker box of the 
magneto, so that if the magneto shaft revolves 
in a clockwise direction looking at the driving 
end, the breaker box lever will be at its top¬ 
most position. If the shaft revolves left-handed 
the lever should be at the bottom limit, and ad¬ 
vanced upward. 

Now revolve the armature shaft in its direc¬ 
tion of rotation until the oval breaker cam 
comes in contact with the roller in the breaker 
bar and begins to separate the platinum contacts. 

If it is desired to start on the magneto side, 
ignoring the battery entirely, advance the spark 
mechanism about one-half or two-thirds of the 
• way and crank as before. No back kick should 
be observed. Do not drive the motor with the 
spark retarded, but as far advanced as the 
motor will permit. 

If the platinum contacts after much usage 
become pitted so that a bad contact results, 
they can be filed flat with a fine file, taking 
care not to file off any more than is necessary. 
Then reset the screw so that the break is not 
more than .025 of an inch. 


The Automobile Handbook 461 

Don’t forget to occasionally brush the dis¬ 
tributer disc and interior of distributer block 
clean of any accumulation of carbon dust. 

The “E U” magneto is a new high tension 
machine designed for four cylinder motors de¬ 
veloping as high as 40 horse power. 

The construction of this magneto embodies 
an aluminum base to which the pole pieces are 
secured, and between which revolves an arma¬ 
ture on two annular ball bearings. The circuit 
breaker is attached to one end of the armature 
shaft and revolves with it. The magneto is 
self-contained, having both a primary and sec¬ 
ondary winding on the armature. 

The high tension winding of the armature is 
connected to a collector ring, imbedded in a 
spool mounted on the driving end of the arma¬ 
ture shaft. Prom this ring a carbon brush leads 
the current through a water-proof holder to the 
center of the distributer disc. 

The cam holder may be shifted to the extent 
of 30 degrees, enabling an advance or retard of 
the spark to be obtained, thereby causing igni¬ 
tion to take place earlier or later. 

The condenser necessary for the protection of 
the platinum points and the proper functioning 
of the machine is placed in the driving head of 
the armature and revolves with it. 

The distributer consists of a disc of insulating 
material having a metal segment to which the 
high tension current is led from the collector 
brush. The distributer block has four small 


462 The Automobile Handbook 

carbon pencil brushes which lead the current to 
the brass connection imbedded in the block, to 
which the plug wires are fastened. The posi¬ 
tion of the segment on the disc can be seen 
through the little window in the face of the 
distributer block for the purpose of setting the 
machine when timing. 

A spark gap for the protection of the arma¬ 
ture winding is located at the inside end of the 
brush holder under the magnets. 

The main bearings of the magneto are pro¬ 
vided with oil cups, and a few drops of light 
oil every 1,000 miles are sufficient to lubricate 
them. The breaker arm should be lubricated 
with a drop of light oil applied with a toothpick 
to the hole in the bronze bearing pivoted on 
the steel pin. The cams are lubricated by a felt 
packing, and a little oil applied to the holes in 
the edge of the cams will last a long time; any 
surplus oil should be removed and care taken 
to prevent any oil getting on the platinum 
points. 

The proper distance between the platinum 
points when separated should be .020 or 1/50 of 
an inch. A bronze gauge of the proper size is 
attached to the wrench furnished for the adjust¬ 
ment of the platinum screw and lock nut. 

The fibre roller on the end of the breaker arm 
is held in position by a pawl spring. The wear¬ 
ing surface of the roller may be renewed by 
rotating the same a quarter turn, thus bringing 
a new surface to bear on the cam, and as there 


The Automobile Handbook 463 

are four slots in the roller four wearing surfaces 
are available. 

To time the magneto, rotate the crank shaft 
so as to bring the piston No. 1 cylinder 1/16 
of an inch ahead of the upper dead center of 
the compression stroke. With the timing lever 
fully retarted, the platinum points of the cir¬ 
cuit breaker should be about to separate. Some 
motors may require an earlier setting. 

The distributor segment should show in the 
little window in the block and the plug wire to 
No. 1 cylinder should be fastened under the 
brass nut directly over the segment. The rest 
of the plug wires should be fastened in turn 
according to the proper sequence of firing of 
the cylinders to which they lead. 


464 The Automobile Handbook 

MAGNETO WIRING DIAGRAMS. 




Wiring of Bosch Two Spark Magneto, 
Models D and DR 






















































TJie Automobile Handbook 


465 



Wiring for Eisemann Dual Magneto, Model EM 4 



Wiring of Mea Dual Magneto, Model SC 




































































































466 


The Automobile Handbook 




Fig. 220 

Wiring for Kingston Transformer Coil Magnetos, 
Models M and L 


Z?.a ttariaA, 






























































The Automobile Handbook 


467 




Fig. 222 

Wiring for Remy R L Magneto 














































468 


The Automobile Handbook 


4 L 6R£CN 

n C RED 

^ ^ YELLOW 


Mgi$ 

o 

» 

r> 

BATTERIES I * rf-l 

rami J 

'll - 

pj 


\n - 

iJ ID — LJ 



Fig. 223 

Wiring for Remy Magnetos, Models P and 32 






















































































The Automobile Handbook 




Wiring for Simms Magneto Model SU4-D 



Fig. 226 

Wiring for Simms Magneto Model SU4-S 















































470 


The Automobile Handbook 



Models A, B, D, F, 0 and T 



Fig. 228 

Wiring for Splitdorf Magnetos, 
Models S, SS, W, X, Y and Z 






















































The Automobile Handbook 


471 




Transformers 








































472 


The Automobile Handbook 


Induction Coil. The form of coil generally 

used on gasoline cars is known as the jump- 
spark coil. It is of two types, one known as a 
plain or single jump-spark, the other as a vi¬ 
brator or trembler coil. 

A jump-spark coil consists essentially of a 
bundle of soft iron wire, known as the core, 
over which are wound several layers of coarse 
or large size insulated copper wire, called the 
primary winding. Over this are again wound 
a great many thousand turns of very fine or 
small wire, known as the secondary winding. 

Inertia. Inertia is that property of a body 
by which it tends to continue in the state of 
rest or motion in which it may be placed, until 
acted upon by some force. As used by the non¬ 
technical, it is almost universally employed in 
the former sense, i. e., that of the resistance 
which a body offers against a change in its po¬ 
sition, an inert body usually being intended, so 
that the definition is perfectly correct so far 
as it goes. The popular impression is that only 
inert bodies have inertia, it being likewise gen¬ 
erally thought that a moving body is possessed 
of momentum alone, whereas an object at rest 
is possessed of inertia, and the same object in 
movement has both momentum and inertia. 
Insulating Material. Asbestos, lava, and mica 
are severally used for the insulation of spark 
plugs and sparking devices. 

Vulcanized fiber or hard rubber or even hard 
wood are used for the bases of switches, con- 


The Automobile Handbook 


473 


nection boards and other places. 

India rubber, or gutta-percha form the basis 
of the insulated covering of wires used for elec¬ 
trical purposes. The coils of small magnets and 
the cores of induction coils are usually wound 
with cotton covered wire, or in some instances 
the fine wire is silk covered, as in the case of 
secondary or jump-spark coils. 

Joints, Ball and Socket. To produce a flexible 
joint capable of operation within certain limi¬ 
tations in any direction, the ball and socket 
form of joint is generally used on the ends of 
the rod which connects the arm of the steering 
mechanism with the steering lever attached to 
the hub of one of the steering pivots of the 
front axle. 



Fig. 230 




























474 The Automobile Handbook 

Joints, Knuckle. Swivel or knuckle-joints 
for connecting the steering arm of the wheel, or 
lever steering mechanism to the arms on the 
knuckle-joints of the steering wheels are of va¬ 
rious forms. Figures 230 and 232 show knuckle- 
joints which may be used for the above pur¬ 
pose. They are of simple construction and 
practically inexpensive to make. They may be 
used with any standard drop-forged jaw-ends. 

Joint—Universal. The elementary form of a 
universal-joint or flexible coupling consists of a 
spiral spring. Such a form of universal-joint is 
sometimes used to drive a rotary pump, or a 
small generator on a car. The rear wheels or 
axle of a car are sometimes driven by means of 
a longitudinal shaft with a quarter-turn drive 
on a counter shaft, or a bevel gear drive at¬ 
tached to the differential gear of the rear axle. 
In such cases some form of universal-joint is 
necessary to allow the rear wheels and axle to 
accommodate themselves to the inequalities of 
the road surface. Three forms of universal- 
joints are shown in Figure 233 The upper view 
in the drawings shows the form most generally 
used on motor-cars, for the purposes just de¬ 
scribed. The one shown in the center view will 
allow a greater amount of angular distortion 
than the form shown in the upper view, but is 
of a more expensive construction. Where only 
a slight amount of angular distortion is needed, 
the construction shown in the lower figure in 
the drawing is very suitable, the two jaws or 


The Automobile Handbook 475 

knuckles of the joint being flexibly attached 
by means of a plate of spring steel. 

A form of universal joint, or flexible coup¬ 
ling, of recent introduction, is that making use 
of leather or other flexible material securely 
fastened to two forked members in such a way 
that with the members placed at an angle to 
each other, power is delivered from one to the 
other through the flexible material that is 
fastened to both of them. 

Large powers are transmitted in this way by 
using a ring of heavy material similar to tire 
fabric and fastening the couplings of the two 
shafts to this ring at alternate positions by 
secure fastenings and bolts. The difference in 
alignment is taken care of by the ring of flex¬ 
ible material, and it has been found that this 
form of drive is quite free from trouble, and, 
of course, requires neither lubrication or cover¬ 
ing against dust and dirt. 

The flexible disc universal is largely used on 
motor trucks where the angle between the shafts 
to be joined is comparatively small and not sub¬ 
ject to any great variations in angularity. The 
number of discs may be made in proportion to 
the load to be transmitted. 

The form of compensating joint shown in 
Figure 231 may be operated with the axes of 
the shafts at an angle to each other, or with the 
shafts out of alignment with each other in ver¬ 
tical or horizontal parallel planes, and has quite 
a range of operation with either condition. Both 


476 


The Automobile Handbook 



forms of the device require to have bearings on 
either side, as shown, to insure their proper 
working. 



Fig. 232 





























































The Automobile Handbook 


477 



Fiff. 233 



















































































478 The Automobile Handbook 

Kerosene as a Fuel. Kerosene has been used 

as an explosive power, and crude petroleum is 
gaining favor as an efficient liquid fuel. With 
a specific gravity varying from 0.78 to 0.82. 
and a vapor flashing point at 120 to 125 de¬ 
grees Fahr., kerosene ignites at 135 degrees 
Fahr., and boils at 400 degrees Fahr. Its vapor 
is five times heavier than air, and requires 76 
cubic feet of air to one cubic foot of vapor for 
its combustion, giving 22,000 heat units per 
pound, or 4,000 more than gasoline. 

In using kerosene as a fuel for the ordinary 
types of gasoline engines it will generally be 
found that the compression may be slightly low¬ 
ered to good advantage. A high grade of rather 
heavy bodied oil must be used and the oil should 
be drained from the crankcase and the case 
washed out at least every five hundred miles. 

It is difficult, if not quite impossible, to start 
the engine using kerosene as a fuel unless the 
cylinders and cooling water are still hot from 
previous running. Carburetors for the use of 
kerosene are therefore generally so arranged 
that gasoline, or a mixture of gasoline and kero¬ 
sene, may be used for starting when cold. Two 
separate carburetors, joined by means of a two 
way valve, may be used or a single carburetor 
with two float bowls, one for each fuel, may be 
employed. Still other types provide a small 
amount of gasoline which burns for a minute or 
two after starting. The fuel itself, also the in¬ 
coming air should be well heated. 


The Automobile Handbook 


479 


"Water vapor from an additional jet may or 
may not be used with the kerosene mixture. 
Under heavy loads at low speeds water may be 
added to the mixture with good results in pre¬ 
venting preignition. 

Knocking—Locating Cause of. Tracing a 
knock is sometimes a puzzling job. It may be 
in one of the main bearings of the engine, in 
the camshaft bearings, in a loose valve lifter, 
in a loose camshaft gear key, in a loose pump 
or magneto drive coupling, an unsuspected 
loose bolt between two parts supposed to be 
fast, or in any of a dozen, or score of other un¬ 
suspected places. A valuable aid in locating a 
mysterious knock is a flexible speaking tube 
such as is used with phonographs. One end of 
such a tube can be held to the ear and the 
other moved about from point to point until 
the exact spot is found where the noise is loud¬ 
est. Another aid is a light bar of iron, one end 
of which is pressed against the part where the 
knock is suspected and the other touched to the 
forehead or the teeth, when the sound is clearly 
transmitted. 

Knocking or pounding is an inevitable warn¬ 
ing that something is wrong with a motor. It 
may be due to any of the following causes: 

Premature ignition: The sound produced by 
premature ignition may be described as a deep, 
heavy pound. 

Using a poor grade of lubricating oil will 
cause premature ignition. The carbon from the 


480 


The Automobile Handbook 


oil will deposit on the head of the piston in 
cakes and lumps, and will not only increase the 
compression, but will get hot after running a 
short time and will ignite the charge too early, 
and thereby produce the same effect as advanc¬ 
ing the spark too much. If this is the cause the 
pounding will cease as soon as the carbon de¬ 
posit is removed from the combustion chamber. 

Badly worn or broken piston-rings. 

Improper valve seating. 

A badly worn piston. 

Piston striking some projecting point in the 
combustion chamber. 

A loose wrist-pin in the piston. 

A loose journal-box cap or lock-nut. 

A broken spoke or web in the flywheel. 

Flywheel loose on its shaft. 

If the spark plug be placed so as to be ex¬ 
actly in the center of the combustion space, an 
objectionable knock occurs, which has never 
been fully explained. In some motors it ren¬ 
ders a particular position of the spark control 
lever unusable; this form of knock disappears 
either on making a slight advance or retarda¬ 
tion of the ignition. 

Explosions occurring during the exhaust or 
admission stroke. This is almost always due to 
a previous misfire, and it is prevented by stop¬ 
ping the misfires. 

If the ignition is so timed that the gases reach 
their full explosion pressure during the com¬ 
pression stroke, that is, if the spark be unduly 


The Automobile Handbook 481 

advanced when the motor is not running at a 
high speed, an ugly knock occurs, and great 
pressure is developed on the crank-pin bearing, 
wrist-pin, and connecting rod. The result may 
be the bending or distorting of the rod. 

The crank-pin may not be at right angles to 
the connecting rod. 

The bearings at either end of the connecting 
rod may be loose. A knock during the explo¬ 
sion stroke, and also at each reversal of the 
direction of the piston. 

If the crank shaft is not perfectly at right 
angles to the connecting rod, the crank shaft 
and flywheel will travel sideways so as to strike 
the crank shaft bearings on one side or the 
other. 

Lamps, Electric. The small incandescent 
lamps used for automobile lighting are almost 
invariably of the tungsten filament variety. 
Two types are in use, considered from the bulb 
standpoint, one of which exhausts the air from 
the bulb until a high degree? of vacuum is 
secured, and the other one of which replaces 
the air with the inert gas, nitrogen. One is 
called the vacuum bulb and the other the nitro¬ 
gen bulb. Two types of bulb base are in use, 
the single contact, in which one side of the cir¬ 
cuit is secured through metal of the base, and 
the double contact with two insulated leads. 
Lamp bulbs vary in diameter from % to 2-1/16 
inches. 

Lighting, see Starting and Lighting Systems 


482 The Automobile Handbook 

Lubrication. To ensure easy running, and 
reduce the element of friction to a minimum it 
is absolutely necessary that all surfaces rubbing 
together should be supplied with oil or lubri¬ 
cating grease, but it is also a fact, not so well 
understood, that different kinds of lubricant 
are necessary to the different parts or mechan¬ 
isms of a motor car. 

As the cylinder of an explosive motor oper¬ 
ates under a far higher temperature than is 
possible in a steam engine, consequently the oil 
intended for use in the motor cylinders must 
be of such quality that the point at which it will 
bum or carbonize from heat is as high as possi¬ 
ble. 

While a number of animal and vegetable oils 
have a flashing point, and yield a fire test suf¬ 
ficiently high to come within the above require¬ 
ments, they all contain acids or other sub¬ 
stances which have a harmful effect on the 
metal surfaces it is intended to lubricate. 

Lubricating Oils. The qualities essential in 
a lubricating oil for use in motor cylinders in¬ 
clude a flashing point of not less than 500 de¬ 
grees Fahrenheit, and fire test of at least 600 
degrees, together with a specific gravity of 25.8. 

At 350 to 400 degrees Fahrenheit, lubricating 
oils are as fluid as kerosene, therefore the ad¬ 
justment of the feed should be made when the 
lubricator and its contents are at their normal 
heat, which depends on its location in the car. 
Steam engine oils are unsuitable for the dry 


The Automobile Handbook 


483 


heat of motor cylinders in which they are de¬ 
composed whilst the tar is deposited. 

All oils will carbonize at 500 to 600 degrees: 
Fahrenheit, but graphite is not affected by 
over 2,000 degrees Fahrenheit, which is the ap¬ 
proximate temperature of the burning gases in 
an explosive motor. The cylinder of these mo¬ 
tors may attain an average temperature of 300 
to 400 degrees Fahrenheit. So that graphite 
would be very useful if it could be introduced 
into the motor cylinder without danger of clog¬ 
ging the valves, and could be fed uniformly. 
These difficulties have not yet been overcome. 
Graphite is chiefly useful for plain-bearings and 
chains. 

The film of oil between a shaft and its bear¬ 
ing is under a pressure corresponding to the 
load on the bearing, and is drawn in against 
that pressure by the shaft. It might not be 
thought possible that the velocity of the shaft 
and the adhesion of the oil to the shaft could 
produce a sufficient pressure to support a heavy 
load, but the fact may he verified by drilling a 
hole in the bearing and attaching a pressure 
gauge. 

Roller and ball-bearings provide spaces, in 
which, if the oil used contains any element of 
an oxidizing or gumming nature, a deposit or 
an adhesive film forms upon the sides of the 
chamber, the rollers or balls, and the axle. This 
deposit will add to the friction, hence it is the 


484 The Automobile Handbook 

more important to use a good oil, or a petro¬ 
leum jelly in such bearings. 

Air-cooled motors, being hotter than water- 
cooled, must have a different lubricant, or one 
capable of withstanding higher temperatures. 

The effect upon animal or vegetable oils of 
such heat would be to partially decompose the 
oils into stearic acids and oleic acid and the con¬ 
version of these into pitch. Such oils are there¬ 
fore inadmissible for air-cooled motor use. 

Mineral oils are not so readily decomposed 
by heat, but at their boiling points they are 
converted into gas, and any oil, the boiling 
point of which is in the neighborhood of the 
working temperature of the motor cylinder, is 
useless, as its body is too greatly reduced to 
leave an effective working film of oil between 
the cylinder and the motor piston. 

The essentials for the proper lubrication of 
air-cooled motors are: 

That the oil should not decompose. 

That it should not volatilize, as this will re¬ 
sult in carbon deposits. 

That its viscosity should be equal to that of 
a good steam engine oil at similar temperatures. 

That it should be fluid enough to permit of 
its easy introduction into the cylinder. 

That it will have no corrosive effect on the 
cylinders and no tendency to gum. 

That it will not oxidize with exposure to air 
and light. 

The specific gravity of an oil is the ratio of 


The Automobile Handbook 


485 


weight of a volume of oil to that of an equal 
volume of water. 

The fire point is the degree of heat at which 
oil begins to bum with a steady flame. 

The flash point is the degree of heat at which 
the oil begins to give a slight explosion or flash 
from the evolved gas when a flame is held close 
to the surface of the heated oil. 

The cold point is the degree of temperature 
at which the oil begins to thicken from chilling. 

The viscosity is the property of cohesion, or 
the ability of the particles of the oil to cling to 
each other; also adhesion, or the ability of the 
oil to cling to surfaces with which it comes in 
contact. 

The meaning of the term “body,” as used in 
describing oils, is the oil’s power of resistance 
to pressure and high heat without breaking down 
and losing its lubricating qualities. An oil of 
good body spreads evenly over the surfaces to 
be lubricated and maintains an even thickness 
of film. 

Flywheel Oiling Systems. In the Ford fly¬ 
wheel system of oiling illustrated in Fig. 234, 
the flywheel casing serves as an oil reservoir, 
and the rotation of the wheel throws the oil up 
into pockets, from whence it is conducted 
through pipe^to the crank-case. The angle of 
the pipes is such that even on extreme grades 
• there is sufficient drop to insure a flo.w of oil. 
A depression M is found in the crank case be¬ 
neath each connecting rod, in order to limit 


486 


The Automobile Handbook 


the amount of oil carried in the crankcase, and 
also to insure an even level of oil within the 
case. 



% 


Drilling Oil Passages in the Crank Shaft. 
Pigs. 235 and 236 show two different methods 
of drilling the crankshaft to convey the oil to 





























The Automobile Handbook 


487 


the crankpins, and it will be noticed that the 
oil holes discharge at the highest point of the 
revolution, corresponding to the position of the 
piston at the beginning of the power or firing 
stroke. The supply is received by the main 
bearings from the oil pump and the oil hole in 
the shaft, coinciding with that from the oiler 
has a little oil forced in each revolution and, 
generating centrifugal force throws it rapidly 
through the passages. The majority of modern 
motors are equipped with splash lubrication 
and have the connecting rods dip into the oil 



Fig. 235 


each revolution and splash it all over the inside 
of the crankcase. Some types are equipped 
with a scoop pointing in the direction of rota¬ 
tion, at the lower end of a passage connecting 
with the crank pin. The oil is sent into these 
passages with considerable force, owing to 
speed of rotation, thus assuring sufficient oil to 
the connecting rod bearings. 

This is worked to the ends of the bearing and 
thrown off in the shape of a fine mist that pen¬ 
etrates to every part of the crankcase. The oil 
splashed onto the lower cylinder walls and not 






























488 The Automobile Handbook 

carried up by the piston is caught in little 
troughs, cast in the crankcase and drilled so 
that the oil runs down to the main bearings. 
In addition to the pipe from the oiler, the bet¬ 
ter designs provide an oil wick, or an oil ring 
or chain, all types carrying oil from a shallow 
pocket corded in the bearing cap, the wick by 
capillary attraction, and the rin^ or chain, re¬ 
volving with the shaft, their lower ends im¬ 
mersed in the oil will carry up a considerable 
quantity that will spread over the shaft. This 



Fig. 236 


oil ring system is used very successfully in elec¬ 
trical machinery. With a splash lubrication it 
is advisable to drain the crankcase at frequent 
intervals, and also to put in a fresh supply of 
oil. 

Care should be exercised to select heavy oil 
for air-cooled engines or old engines, and a com¬ 
paratively light oil for new cars. 

Cylinder Oil Testing. There are really 
two parts to the fire test, as it is called. One is 
the test for flash point. This may be determined 


























The Automobile Handbook 


489 


as follows: Take two pieces of glass of the 
same size, and large enough to cover a small 
glass beaker. In one of them cut a couple of 
notches. These are for two purposes. One is 
for the thermometer and the other for the flash 
point determination. Insert a thermometer in 
the beaker, filled with the oil under test. Place 
the notched glass over this and the other piece 
of glass over that, taking care to cover the 
notch not in use. Now uncover this notch, note 
the temperature, and apply a lighted match to 
the opening. If nothing results, warm the oil 
slowly over a flame to a higher temperature 
and take another trial and reading. Continue 
the test until upon the application of the 
lighted match the oil vapor over the oil flashes. 
The thermometer reading at that point gives 
the flash point. The glass plates may now be 
removed, and heating continued. The match is 
applied at similar intervals, until finally the oil 
burns, which will usually occur at about 50 de¬ 
grees above the flash point. 

An additional test is for precipitation at a 
known temperature. This is also made in a 
beaker. Two ounces is the usual amount. It 
is heated to the desired temperature, at which 
the oil may change color, but must not show a 
precipitation. Still another good oil test is the 
evaporation test. This is the result of slow 
heating, and the usual specification is that the 
oil shall not lose over 5 per cent, of its volume 
when heated to 150 degrees Fahr. for 12 hours. 


490 


The Automobile Handbook 


Lubricating Systems: 

Full Force Feed. Oil is forced by pump 
pressure to the main bearings and, by means 
of drilled holes in crank webs, to crank pins and 
through hollow connecting rods, or oil pipes 
attached thereto, to the wrist pins. Oil returns 
to sump, or reservoir, and is circulated again. 

Force Feed. Oil is forced by pump pressure, 
or the centrifugal force of the revolving fly¬ 
wheel, to main bearings and through drilled 
holes in crank webs to crank pins. The w^rist 
pins and cylinder are supplied by oil thrown 
from connecting rods. The connecting rods do 
not dip. Oil returns to sump, or reservoir, and 
is circulated again. 

Force Feed and Splash. Oil is forced by 
pump pressure, or the centrifugal force of the 
revolving flywheel, to the main bearings and 
through drilled holes in the crank webs, to crank 
pins. The oil from the main bearings falls to 
wells in the bottom of the crank case, or to ad¬ 
justable troughs, into which the connecting rods 
dip and splash oil to all parts of the engine. 

Splash. A constant level is maintained in the 
crank case by an overflow to the sump, or reser¬ 
voir, below, whence the oil is circulated again. 

Lubrication of Gears and Clutches. The 
modern ball-bearing gear box requires but lit¬ 
tle attention. Periodic filling with suitable lub¬ 
ricants is sufficient. On chain-driven cars the 
gears and differential are usually exposed by 
lifting one cover. On shaft-driven cars the 


The Automobile Handbook 


491 


differential and rear axle system requires a cer¬ 
tain amount of attention, as too much oil in the 
differential is liable to leak through the axle 
sleeve and hub, usually getting on the brake 
drums. If this happens, the best thing to do is 
to jack the wheel up and squirt gasoline on the 
drum, slowly revolving it meanwhile. Manu¬ 
facturers usually put a plug in the differential 
case showing the proper height at which to keep 
the oil level. The gear box should be kept a 
little less than half full. If too much is put in, 
the oil will be thrown out of the shaft and 
bearing housings, but a little leakage does no 
harm as there is always dust present and the 
oil leaking will serve to fill the crevices and 
make the case dust-tight. In regard to the 
wheels, universal joints, clutch, and many lit¬ 
tle places about the car, all need attention oc¬ 
casionally as almost any motor car driver 
knows. 

The wheels should be cleaned and packed 
with grease once or twice a season, universal 
joints at intervals necessarily shorter. Latest 
designs provide for their lubrication through 
the shaft from the gear box. Earlier types are 
best packed in grease and enclosed in a leather 
boot. On many shaft-driven cars, where the 
shaft runs through a sleeve, daily attention 
should be given. The lack of a few drops of 
oil may rob the car of 50 per cent of its power. 
Multiple disc clutches use oil, or an oil and ker¬ 
osene mixture, and the tendency seems to be 


492 The Automobile Handbook 

for the oil to gum. Their action when slipping 
or dragging is sufficient indication as to when 
they are in need of attention. Leather-faced 
clutches will work much better when cleaned 
with kerosene and given a dose of neatsfoot or 
castor oil. The oil should be spread over the 
surface of the leather by using a long knife 
blade, or by running the motor for a few mo¬ 
ments with the clutch released. When treating 
the clutch leather this' way it is better to let 
it stand over night if possible, and with the 
emergency brake lever, or a block of wood 
against the pedal hold the clutch disengaged. 
A hand oil can with a long spout is almost in¬ 
dispensable, and the starting crank, the steer¬ 
ing pivots and connections, and the spark and 
throttle connections, gear control and emer¬ 
gency brake levers, clutch and brake pedals, 
shafts and connections and the fan bearings 
will all work much quieter and sweeter for a 
few drops of oil regularly. It is the practice of 
drivers to fill the oil can from the cylinder oil 
supply and this practice is to be commended, 
as many lower grade oils contain acids enough 
to etch steel. 

Gear Case and Rear Axle. It is a familiar 
fact that the gear case requires to be periodic¬ 
ally emptied of oil, and the accumulated metal 
grit washed out before fresh oil is supplied. The 
same is true of the rear live axle casing, except 
that the gears in the axle do not clash and 
therefore do not wear out as fast as the change 


The Automobile Handbook 493 

speed gears. At least once in a season the oil 
in the rear axle should be drained out, a liberal 
supply of kerosene introduced, and the axle 
jacked up while the engine is run to agitate the 
oil and wash out the differential, etc. 

Magnetic Gear Shift. The electric gear shift 
may be said to consist of two units, the “ shift¬ 
ing assembly,” or group of magnets attached to 
the transmission case, and the “selector-switch,” 
or push-button group, located on the top of the 
steering column. The electrical current required 
to energize the magnets is derived from a stor¬ 
age battery, Fig. 237, ordinarily supplied as 
part of the starting and lighting systems on all 
cars. 

The selector-switch is made up of a number 
of buttons, one for each speed, and one for the 
“neutral” which has not electrical connection. 
There is also a button for operating the horn. 
These buttons are provided with arched, lami¬ 
nated contacts of copper, backed up with a steel 
spring and insulated from the button proper. 
The top of the switch carries a locking-plate for 
locking any button which may be depressed and 
also carries an interlock, which makes it impos¬ 
sible to press down more than one button at a 
time. At the bottom is a hard rubber base, 
which carries a copper contact for each button 
and a contact common to all speeds. It also 
serves as a base for the return spring provided 
for each button. 


494 


The Automobile Handbook 


The wiring, Fig. 238, consists of a lead pass¬ 
ing from each coil through a terminal block to 



its particular speed button on the selector- 
switch, while the other lead from the coil is 
joined to- a neutral wire directly through the 











The Automobile Handbook 495 

terminal block to the battery, with a master- 
switch intervening, while another wire from the 
battery passes through the terminal block to the 
contact of the selector-switch which is common 
to all speeds. The current travels from one ter¬ 
minal of the battery through the depressed push 
button on the selector-switch, down and around 
the coil selected, and then back to the other ter¬ 
minal of the battery. 



IS MOUNTED ON TOP OF TRANSMISSION CASE. 

Fig. 238 

Connections of the Magnetic Gear Shift 
The Vulcan electric gear shift mechanism con¬ 
sists of a case which is attached to the transmis¬ 
sion housing. This case, in turn, carries the 
magnets or solenoids. These in turn surround 
the plungers on which the shifting forks which 
move the sliding gears in the transmission are 
mounted. In this case, also, is carried the oper¬ 
ating mechanism by means of which -the gears 






























496 The Automobile Handbook 

are mechanically drawn to their neutral position 
through a connection with the clutch pedal. The 
case is divided into two compartments, the smalh 
er of which is a pocket in which the operating 
mechanism for the neutralizing of the gears and 
the operation of the master-switch is carried. 
This compartment is entirely enclosed on the 
bottom, and is not open to the transmission case. 

The neutralizing mechanism consists of two 
shafts on which cams are mounted. One of these 
shafts carries a pawl which engages with a latch 
on a rocker arm. Upon the opposite end of this 
rocker arm shaft is mounted a lever through 
which the connection with the clutch pedal is 
made. 

Assuming that all gears are in a neutral posi¬ 
tion (that is, the sliding gears are not in mesh), 
and it is desired to start, the first speed button 
on the selector-switch is depressed, closing one 
break in the electric circuit. The operating 
lever and the shaft on which it is mounted are 
rotated and the master-switch is pulled into en¬ 
gagement through its connection with the oper¬ 
ating mechanism which engages the switch stem. 
As the gear flashes into mesh, and is within % 
inch from being “home,” the master-switch 
snaps out instantly, due to the action of the 
master-switch spring, thus breaking the electric 
circuit. The actual time of engagement during 
which current is being drawn from the battery 
is less than 1/3 of a second. 

Being in first speed, and desiring to proceed 


The Automobile Handbook 


497 


to another, the other speed button upon the se¬ 
lector-switch may be depressed at the conveni¬ 
ence of the driver. Then, when it is desired to 
shift, the clutch is fully depressed as before. 

As the neutralizing cams rotate toward the 
center, they press against a boss on whichever 
side the gear is in engagement. This mechanic¬ 
ally pulls the shifter fork and gear with which 
it is engaged back to neutral position, before the 
next shift can be made. The electric circuit is 
again made complete, the current flows from the 
battery through the solenoid selected and the 
proper gear immediately jumps into engage¬ 
ment. This action is the same for all speeds 
in the transmission. 

Should it be desired to stop, the neutral but¬ 
ton on the selector-switch is pressed. This action 
throws any other button which may have been 
depressed out of contact, that is, it automatically 
raises any other button which may have been 
depressed previously. 

Any selection may be made, at any time, by 
pressing any push button on the wheel. This 
selection, however, does not necessarily influence 
the changing of the gears in the transmission. 
In fact, nothing happens until the master-switch 
is closed by the pressing, all the way down, of 
the clutch pedal. 

In the operation of this device the clutch 
pedal may be slipped or fully released without 
any action taking place in the gear shift mech¬ 
anism itself. This is due to the fact that the 


498 


The Automobile Handbook 


operating lever is attached to the clutch pedal 
by means of an operating rod provided with a 
link mechanism, which allows the clutch pedal 
to fully release the clutch before it starts to pull 
on the operating lever. 

Magnetism. A piece of iron or steel may be 
made a magnet under the influence of another 
piece that is already magnetic or by being acted 
upon by the electrical influence from a conductor 
carrying current. 

The magnetism in a piece of iron or steel is 
supposed to consist of a circuit and the path of 
this circuit through the magnet and the space 
surrounding it is called the path of the magnetic 
line of force. 

These lines of force pass through the metal 
of the magnet from one end to the other and 
after issuing from the magnet, travel through 
the surrounding space to re-enter it again as 
shown in Figure 239. The end of the magnet 
at which the magnetic lines of force enter the 
metal is called the South or negative pole, while 
the end from which the lines of force issue is 
called the North or positive pole. 

Magnetic lines of force reside in and act from 
iron and steel only, but they will pass through 
all other materials almost as though these other 
materials were not in their way. 

A piece of hardened steel which has been 
made a magnet has the ability to tetain its mag¬ 
netism for a long period of time unless acted 
upon by outside forces such as heating or ham- 


The Automobile Handbook 


499 


mering. Such a piece of steel is called a per¬ 
manent magnet. 

These metals, when soft, carry the lines of 
force as readily as when hardened, but they 
remain magnetic and have the properties of 
magnets only while in the field of other mag¬ 
nets or of coils of wire carrying current which 
produces magnetism in the iron. 




Fig. 239. 


Magneto; see Ignition, Magneto. 

Muffler, Exhaust. When the exhaust gases of 
an explosive motor are allowed to pass out 
through the exhaust pipe directly into the at¬ 
mosphere,. the sharp explosions rapidly suc¬ 
ceeding each other are very annoying, and it 
is for this reason that the device termed an 
exhaust muffler is, or at least should be, used. 










500 The Automobile Handbook 

Various types of mufflers are in use, each no 
doubt possessing its own particular merit. The 
function of the muffler is to deaden the noise of 
the escaping gases, and the general require¬ 
ments of the device are as follows: (1) It must 
be built strong enough to withstand the force 
of any explosion liable to occur within it, due 
to the escape of an unexploded charge, which 
may take place in one of the engine cylinders. 
(2) It must check the velocity of the escaping 



MUFFLER 


Fig. 240 

gases without causing too much back pressure 
on the motor. (3) It must deaden the- noise. 
The last two requirements may be attained by: 
(a) Breaking up the gases into a number of 
fine streams; (b) Allowing the gases to expand 
and cool; (c) Reducing the pressure of the 
gases, until they are as nearly as possible at 
atmospheric pressure. 

The terminal or exhaust pressure ranges at 
from 30 to 50 pounds per sq. in. above atmos¬ 
pheric pressure, while the temperature will be 
800 to 1100 degrees F. 






The Automobile Handbook 


501 


Muffler Cut-Outs. Mufflers are generally 
equipped with muffler cut-outs, which by-pass 
the gas so that it exhausts direct into the at¬ 
mosphere with its attendant noise. There are 
three reasons why they are so equipped, namely: 
to tell if the engine is exploding regularly; to 
clean the exhaust pipe; to have it act as a safety 
valve in case of explosions in the muffler. If the 
power of the engine increases when the muffler 
is cut out, it is a sure sign that the muffler is of 
defective design or needs cleaning. 

Muffler Cut-Out Valve. One form of cut¬ 
out valve is shown in Fig. 241. It is inserted 
in exhaust pipe P, by saw T ing a hole in its under 



Fig. 241 

Muffler Cut-Out Valve 


side. The cut-out valve housing clamps to the 
pipe by a couple of V-clamps. The valve is 
carried in a cylindrical compartment under the 
exhaust pipe, and consists of a spring closed 
poppet valve a little larger in diameter than the 
internal diameter of the exhaust pipe. It opens 
against the exhaust pressure to prevent leakage. 















502 The Automobile Handbook 

Care of Mufflers. From time to time, all 
mufflers should be cleaned, because it will be 
found that they will contain a considerable 
amount of carbon deposists. These deposits not 
only tend to increase the back pressure, but 
they retain the heat of the exhaust, thus al¬ 
lowing the gases to escape at a higher tempera¬ 
ture than they should. A muffler should be 
taken apart and cleaned once a year, or oftener 
if there are any indications of loss of power, 
resultant from back pressure. 

A frequent cause of damaged or broken muf¬ 
flers is the practice of ignition testing employed 
by some mechanics. In case of trouble with 
either source of ignition, the car is run at a 
rather high speed on the good system, and the 
ignition switch is then quickly turned to the 
faulty side. If no explosions result, the switch 
is again changed. In the time during which no 
explosions occurred in the engine, the unburned 
mixture was pumped back} into the muffler* 
When the switch is thrown to the good side, 
the first power stroke sends a flame into the 
muffler with the result that an explosion occurs 
there, usually damaging the muffler seriously. 

Packing. Packing or material for making 
gas, or water-tight joints is of various kinds. 
Asbestos packing comes in sheets, called asbes¬ 
tos paper or board, in the form of woven cloth, 
and also as string or rope. Rubber packing is 
made in sheets, either plain or with alternate 
layers of canvas and rubber. Some forms of 


The Automobile Handbook 503 

packing are known as Rubberbestos, and Vul- 
cabestos, and are made of asbestos, impregnated 
with rubber and afterwards vulcanized. 

Picric Acid. Gasoline will absorb or take up 
about 5 per cent of its weight of picric acid. 
The addition of a small quantity of kerosene 
will enable the gasoline to absorb about 10 per 
cent of pircric acid. 

Picric acid is only dangerous when fused, or 
when in a highly compressed state. 

An increase in motor efficiency of about 20 
per cent is claimed for the picric-gasoline mix¬ 
ture. 

About three-tenths of a pound of picric acid 
is required for each gallon of gasoline. The 
mixture should be allowed to stand for two 
days, agitating occasionally during this time, 
then strain through two or three thicknesses 
of very fine muslin before using. 

It must be remembered that picric acid is an 
etching ingredient, which is another way for 
saying that it will destroy the cylinder walls. 

The explosive force of picric acid is very 
much overrated. If thrown upon a red hot 
plate of iron, it simply burns with a smoky 
fiame, and striking a small quantity of it upon 
an iron anvil will not explode it. 

Polarity. To ascertain the polarity of the 
terminals of a storage battery or light circuit, 
place the ends of the wires on the opposite ends 
of a small piece of moistened litmus paper. The 


504 


The Automobile Handbook 


wire on the side of the paper which has turned 
red is the negative pole of the battery. 

Porcelain. Porcelain tubes used for the in¬ 
sulation of the center rod of a spark plug have 
higher insulative properties than lava or mica, 
but on account of the liability of the porcelain 
to break from too sudden change of tempera¬ 
ture, it is not as reliable as other forms of in¬ 
sulating material. 

Pounding—Causes of. The most obvious 
cause of pounding is that of a spark advanced 
too far. This, however, nearly always occurs 
upon hills, in deep sand or mud, or elsewhere, 
whenever the engine is laboring very hard. In 
the case of too far advanced spark, manipula¬ 
tion of the spark would only make the pound 
worse than ever. So, too, if the spark was nor¬ 
mally set too far advanced, it would pound 
more at high speeds than at slow, just the re¬ 
verse of the actual case. 

Preignition causes pounding, and is itself 
caused by overheated piston or cylinder walls. 
Glowing points or deposits of carbon within 
the cylinder, as-well as faulty or uncertain igni¬ 
tion also cause it. Leaks in the chamber are 
sometimes' the cause of pounding, so too, are 
looseness of parts. Among the latter may be 
cited: connecting rod bearings, main bearings, 
loose flywheel, cracked flywheel, other lost mo¬ 
tion. Beyond these things, the only other cause 
of pounding is that of some moving part which 
strikes as it rotates. 


The Automobile Handbook 


505 


Preignition—Causes of. If the inside sur¬ 
faces of the combustion chamber are free from 
sharp corners or projections formed in casting, 
preignition is probably due to the combined in¬ 
fluences of high compression, and carbon or dirt 
on the piston head. Next to the exhaust valve 
itself the piston head is the hottest part of the 
engine, since it cannot be water cooled. For 
this reason it is much more important to keep 
the piston head clean than the other surfaces 
exposed to flame, and this is best accomplished, 
first, by the use of a good non-carbonizing oil, 
and, second, by thoroughly screening the air 
intake. If preignition is troublesome it will 
pay to fit a dust screen underneath the engine 
in case none is already provided, since what¬ 
ever dust touches the piston head will be held 
there by the oil, and will be fully as effective in 
causing preignition as the same amount of 
carbon. The intake itself should draw air 
through at least one, and preferably two or 
more fine wire gauze screens of sufficiently large 
area to permit the air to pass through them 
slowly. These screens should be removable, and 
should be inspected, and cleaned with gasoline 
and a toothbrush as often as may be necessary. 
It will be found that the fitting of a suitable 
dust screen beneath will make an immense dif¬ 
ference in the amount of cleaning, which the 
gauze screens require. In the manufacture of 
high classed motor cars the greatest care is 
taken in scraping the walls and dome of the cyl- 


506 


The Automobile Handbook 


inder castings forming the combustion space, 
the aim being to remove every projection that 
might cause a pre-ignition point as also to re¬ 
move every burr, or rough spot to which for¬ 
eign matter would adhere. The lubrication 
system of a car is a most important factor in the 
elimination of preignition due to the proper 
amount of oil being fed to the cylinders. 

When a back kick occurs and the crank-shaft 
rotates in the reverse direction, that rotation 
must first be stopped and a rotation started in 
the correct direction. To stop the back kick or 
reverse rotation requires power, and to again 
start the correct rotation calls for power. The 
forces that stop the back kick are, the arm of 
the persbn cranking the weight of the rotating 
flywheel, and forcing one of the other pistons 
to compress the mixture. The force that starts 
the flywheel in the correct direction is the ex¬ 
ploding charge of gas in cylinder No. 2 as 
illustrated in Fig. 242, in which the piston in 
No. 1 cylinder has not reached the top dead 
center on the compression stroke when the 
spark occurs and the reverse movement of the 
crankshaft starts. In tracing out what happens 
the valve locations must be considered. Both 
valves—intake and exhaust—in No. 1 cylinder 
are closed on the compression stroke and they 
will remain closed on the back kick stroke. 
Had the motor been running, No. 2 cylinder 
•would have been going down on the explosion 


Fig. 242 

Diagram Illustrating Theory of Back Firing 


The Automobile Handbook 


507 











































































508 


The Automobile Handbook 


stroke of the piston, but as there was no previ¬ 
ous explosion, the motor having been idle, the 
cylinder would be filled with mixture, with 
both valves closed, as they always are on the 
explosion stroke. The piston in this cylinder 
was normally going down; but, as soon as the 
back-fire occurred, the piston would start up 
and the valves remaining closed, the mixture 
would be compressed. This pressure would help 
to stop the back kick, and as soon as the power 
of back-kick was over the compression would 
start the piston down on the proper explosion 
stroke, which would prove of sufficient power 
to carry the motor past the firing point in the 
other cylinders. Cylinders 3 and 4 would not 
be factors at all, in that the piston in No. 3 
would, when the back-kick occurred, be near 
the bottom or end of the suction stroke with the 
intake valve open, and when the reverse action 
of the piston set in it would start rising, simply 
driving the mixture out through the open intake 
valve and through the carbureter. Cylinder No. 
4 was near the completion of the exhaust stroke 
when the back-fire started, and the exhaust 
valve was open. During the reverse motion 
caused by the back fire, the piston would start 
descending, the exhaust valve remaining open, 
exhaust gases would be drawn into the cylinder 
from the exhaust pipe. 

Other causes of back firing are, 

(1) A WEAK mixture. Bearing in mind that 
the mixture is the fuel of the engine, and that 


The Automobile Handbook 509 

as in a stove, the character of the fuel influences 
its manner of burning, it will be evident that 
like poor wood, slaty coal, or other imperfect 
fuel, a weak mixture is a slow burner. This is 
point number one. Proportionate to the speed 
at which it is running, the motor has a certain 
sharply defined period of time in which it must 
complete each part of its cycle, if it is to operate 
satisfactorily. Should' the parts of the cycle 
lap, or run over into one another, there is bound 
to be a hitch of some kind. The use of a very 
weak mixture causes just such a hitch by rea¬ 
son of the' fact that it continues burning for 
some time after the completion of the part of 
the cycle during which it is supposed to func¬ 
tion, i. e., the power stroke. In fact, it is still 
burning when the inlet valve opens to take in 
a fresh charge, and as its burning in the cylin¬ 
der maintains considerable pressure therein, the 
latter, on the lift of the inlet valve, escapes 
through it and the carbureter with a pop, 
exactly similar to that of an unmuffled exhaust 
except that it is weaker. The remedy is more 
gas or less air, or sometimes both, and to find 
out just how much of each is required, start 
the motor and very gradually cut down its 
gasoline supply at the needle valve of the car« 
bureter until the motor begins to miss. Then as 
slowly increase the supply until the motor will 
run steadily and without missing on the mini¬ 
mum opening of the needle valve. Lock the 
latter in place. Then speed the motor up by 


The Automobile Handbook 


$\0 

opening the throttle and adjust the spring of 
the auxiliary intake on the carbureter until the 
motor is receiving sufficient air to enable it to 
run and develop plenty of power at all speeds. 

(2) An overheated combustion chamber, 
due to a poor circulation of the cooling water- 
causing self-ignition of the charge before the 
proper time. 

(3) Advancing the ignition point too far 
ahead when the motor is running slowly under 
a heavy load—flywheel has not sufficient mo¬ 
mentum to force the piston over the dead cen¬ 
ter, against the pressure of the already ignited 
and expanding gases. 

(4) The presence of a deposit of carbon 
(soot) or a small projecting surface in the com¬ 
bustion chamber which may become incandes¬ 
cent and cause premature ignition. 


The Automobile Handbook 


511 


Repair Work. In assembling the car the 
engine had best be put together first. When 
putting the pistons in their respective cylinders 
see that the splits or joints in the piston rings 
are^not in line, but are spaced evenly around 
the piston. See that all parts are thoroughly 
clean and that no grit, or stray strands of waste 
happen to be caught on any projection. All 
nuts and bolts should be screwed tight and the 
jaws of the wrench should be properly adjusted 
to them, that the corners of the nuts and cap 
screws may not be rounded off. Insert the cot¬ 
ter pin after each nut has been screwed home. 
In joints where packing is required the old 
packing may be used if it is in good shape. 
Joint faces should, of course, be perfectly clean. 
A stout grade of manila wrapping paper soaked 
in linseed oil will make an excellent packing for 
crankcase and other joints having a good con¬ 
tact surface. 

While the engine is being reassembled it will 
be found advantageous to check up the valve 
timing. To do this, turn the fly-wheel until 
the inlet valve plunger of No. 1 cylinder just 
touches the lower end of its valve stem. At this 
point the line on the fly-wheel indicating ‘ ‘ Inlet 
No. 1 Open” should coincide with the pointer 
on the engine base. If the contact between the 
valve stem and the plunger is made before the 
mark on the fly-wheel lines up with the pointer, 
the valve opens too early. In most cars the 
adjustments may be made by the screw cap and 


512 


The Automobile Handbook 


lock-nut on the plunger. As the valve stems are 
lowered by repeated grindings of the valves, 
the plungers require adjustment occasionally 
to compensate for this movement. Insert a 
piece of paper between plunger and valve stem, 
and by lightly pulling on the paper the time of 
contact and the moment of release may be de¬ 
termined to a nicety. When the paper is held 
tightly, a good contact is assured, and the mo¬ 
ment the paper becomes loose and can be moved 
about, the contact is broken. In many cars the 
reference or index mark on the engine bed is 
omitted; in this case the markings on the fly¬ 
wheel must be brought directly to the top. The 
other inlets and the exhaust valves should then 
be similarly checked up and adjusted. 

Most cars base the valve setting on a 1-32 
inch clearance space between valve stem and 
plunger rod when the valve is closed. This 
may be taken as the minimum amount, and 
should not be increased. A larger amount of 
clearance will cause the exhaust valve to open 
too late, and, the exploded gases not being en¬ 
tirely expelled, the power of the motor will be 
impaired. This clearance is necessary to allow 
for the expansion of the valve stem when it be¬ 
comes heated. 

Too much stress cannot be laid on the neces¬ 
sity of going about the work in an orderly and 
methodical manner. A mechanic who leaves 
parts lying about carelessly will rarely be found 
a good one, and'certainly he is not a proper 


The Automobile Handbook 


513 


model to copy. With care, the amateur owner 
should have no trouble in overhauling, thus bet¬ 
tering the condition of his car and acquiring a 
valuable stock of knowledge. 

Automobile Tools. In Fig. 243 three types 
of valve lifters are shown. B and C are of the 
same principle, and quite efficient in almost any 
case; but A, when properly operated, and on 
its respective motor, is more quickly applied, 



and consequently a time saver. D is a valve¬ 
seating tool, supplied as special equipment by 
one of the large motor car manufacturers. 

In Fig. 244 are shown a couple of spanner 
w r renches and one or two other tools that are 
quite uncommon but quite necessary in the work 
to which they are adapted. A is made from a 
piece of steel tubing and used on packing 
glands—the tube to slip over the shaft—and the 
small lugs at the end engage corresponding 












514 


The Automobile Handbook 


recesses in a packing nut. B is representative 
of a valve-grinder, designed especially for the 
valves in certain motors. The spanner C is re¬ 
quired to conveniently remove certain types of 
cylinder plugs; while D, which approaches the 
conventional, is used in adjusting bearings of 
a particular type. 

There is probably a greater variety of wheel 
and gear pullers now in service than of any 



other special tool. In Fig. 245, A looks very 
much like the standard adjustable wheel and 
gear puller for sale in all supply houses; and 
it practically is the same except that the hooks 
are larger and twisted in opposite directions 
and at right angles to the beam. It is found 
useful in removing road and flywheels and the 
like. B is a non-adjustable tool n%ade especially 
for removing flywheels. C and P are road wheel 
pullers, and are included in the regular equip- 





The Automobile Handboolc 


515 


ment of tools supplied with the cars of two 
prominent manufacturers. C is part of the 
Rambler tool equipment and is used in connec¬ 
tion with their spare wheel; and P represents 
the type of wheel puller supplied by the Pierce- 
Arrow. E is a gear-puller designed to remove 
the half-time-gears of an Oldsmobile, the two 



side-screws being intended to fit into threaded 
holes in the web of the gears. 

Removing Dents. An easy method of remov¬ 
ing dents consists of soldering a piece of wire 
to the bottom of the dent, then pulling the de- 



















516 


The Automobile Handbook 


pressed portion out to its proper position. When 
the dent happens to be in an oil, or gasoline 
tank, or a radiator, an old valve can be most 
effectively used in place of the wire, as shown 

in Fig. 246. 



Fig. 246 

Removing Dent in Gasoline Tank 

Tools Necessary. The following tools should 
be in the car when on the road: 

Monkey wrench, 9 inch. 

Machinist ’s screwdriver. 

Ball pene hammer, one pound. 

Combination pliers, 8 inch. 

Set of double end, or ‘ ‘ S * ’ wrenches. 

Flat file, mill cut. 











The Automobile Handbook 


517 


Three cornered file. 

Round file, six inch. 

Center punch. 

Prick punch. 

Drift punch, flat ended. 

Offset, or “bent-end” screwdriver. 
Cold chisel, three-quarter inch. 
Spark plug wrench. 

Small wire cutting pliers. 

Emery cloth. 

Cotter pin puller. 

Wire brush for spark plugs. 



Fig. 247 

Pouring Parson’s Metal 


Shop Kinks. To reline a journal box with 
Parson’s white brass,'proceed as follows: Pre¬ 
pare a reasonably smooth cast iron plate A, Fig. 
247, which is bored to receive a vertical man¬ 
drel B about 3/16 inch smaller in diameter than 
the finishing bore of the box. An annular brass 
ring C, about % inch wide, and whose in- 













518 The Automobile Handbook 

side diameter is about % inch smaller than 
the outside diameter of the end flange D 
of the box to be lined, is then located on 
the iron plate concentrically with the man- 
dfel, and secured by means of pins or other¬ 
wise. This ring serves as a support for the 
box itself, and in the process of pouring, the 
space between the ring and mandrel is filled 
with white brass which is afterward turned off. 
Any imperfect metal which may be poured will 



Fig. 248 


find its way either into this space or into the 
space above the box, leaving the lining of the 
box itself perfectly sound. The box itself is 
assumed to have been suitably counterbored 
and recessed to hold the lining as shown in the 
sketches E and F, Fig. 248. It is preferable to 
use the arrangement shown at F and allow the 
lining to extend beyond the ends of the box, and 
form the outer surface of the flanges. In this 
case the diameter of the flange formed by the 
lining will be the inside diameter of the sup- 










The Automobile Handbook 


519 


porting ring, which will be slightly smaller than 
the diameter of the flange of the box itself. 

The halves of the box—if it is split—are 
wired together and the box and the mandrel are 
heated' by torches and assembled as shown in 
the sketch. A second ring—not shown—simi¬ 
lar to the supporting ring is placed on the top 
of the box, and all the cracks are luted with 
moist fire clay. Meanwhile, the white brass 
has been melted in a kettle to a fairly high 
heat somewhat higher than tlie pouring temper¬ 
ature. While it is being melted, it is kept cov¬ 
ered by about 1 inch of powdered charcoal, 
which excludes the air. When the maximum 
temperature is reached, the charcoal is quickly 
skimmed off and a handful or two of powdered 
salammoniac is thrown on. The salammoniac 
is immediately volatilized and forms a heavy, 
though colorless gas which shuts off the air 
from the surface of the metal and causes it to 
stay bright. The pouring is then done with all 
possible haste, and on cooling the metal will be 
found perfectly homogeneous and solid. If the 
box is split the lining can be condensed by pen- 
in g. If the box is solid, the lining is simply 
bored to the proper size. 

To Restore a Sagged Frame. A frame which 
is sagged to the extent of permanent deforma¬ 
tion can be restored so as to approximate its 
original shape, by heating it in a charcoal fire 
with an air blast. To do this properly, it will 
most likely be necessary to cut out the rivets, 


520 The Automobile Handbook 

so that the side members can be handled inde¬ 
pendently. A good plan of procedure is to in¬ 
close the bent portion of the frame in a section 
of stovepipe of sufficient size in which the char¬ 
coal fire is built. A length of 1-inch gas pipe, 
closed at one end, and having 5/16-inch holes, 
drilled at intervals of about 6 inches, is laid in 
the bottom of the pipe and furnishes the air 
supply from a bellows. When the charcoal fire 
is well kindled, the frame is introduced upside 
down, and is supported at the ends. The fire is 
then concentrated on the bent portion, and as 
the frame becomes hot it will straighten itself. 
It must be watched carefully and the air blast 
stopped as soon as the frame is seen to be 
straight. Most of the frames used in American 
cars are ordinary carbon steel, and require no 
special treatment. It will be well, however, on 
stopping the air blast to shift the stove pipe to 
a cooler portion of the frame, to permit the 
part which has been straightened to cool as 
quickly as exposure to the air will permit. A 
frame which has been sagged and straightened 
in this manner will require to be trussed to pre¬ 
vent recurrence of the trouble. As conditions 
vary so much the best rule to follow is to ob¬ 
serve the truss arrangement on some similar 
car. The struts should be about 4 or 5 inches 
long, and should be located at the spots where 
the sagging has occurred. The truss rod itself 
should be about % inch in diameter, and drawn 
taut by a turnbuckle, which may be finally 


The Automobile Handbook 


521 


tightened when the chassis has been assembled. 

Spanish Windlass. The old fashioned Span¬ 
ish windlass, in Fig. 249, may be occasionally 
employed where no other hoist is available. It 
is extremely handy in setting, and lining np 
motors, transmissions and rear axles. It con¬ 
sists of a round bar or piece of pipe, a piece of 
rope, and a lever such as a small crowbar or 



jack-handle; all of which are quite common to 
the ordinary repair shop. The round bar is 
laid across the side members of the frame, the 
rope is made fast to the object to be hoisted, a 
loop of it is wound around the bar as shown, 
and the lever inserted in the end of the loop. 
Although this is as old as the hills, it is not un¬ 
common to see a man lying on his back, in a 





522 


The Automobile Handbook 


most uncomfortable position, holding a heavy 
transmission case up into place while another is 
trying to locate the bolt holes, and adjust the 
liners; whereas, if this makeshift windlass were 
employed, one man could raise and set the gear¬ 
box with much less trouble. 

Straightening Spindles. In Fig. 250 a tool 
is shown' which is used in a local repair shop, 
for straightening spindles. The tool, which is 
of heavy construction, is placed in a vise; the 



Fig. 250 

Tool for Straightening Spindles 


spindle is heated to a red heat, the ends cooled 
off with water, and placed between the centers, 
as illustrated. A lever is then placed between 
the bent portion of the spindle and the shank 
of the tool, so that when pressure is brought to 
bear on it, the spindle arm may be brought 
back into its normal position. 

Cleaning Aluminum. Aluminum, such as 
used for foot-boards of cars, may be cleaned by 
using hyposulphate of soda, as this substance is 
a solvent of aluminum tarnish. The dirty sur- 






Fig. 251 


The Automobile Handbook 


523 




































524 


The Automobile Handbook 


face should be washed with a strong solution 
of the hyposulphate; then rinse the surface with 
water and dry. 

Care of Tire Pump Leather. The proper 
lubricant for the cupped leather washer of the 
tire pump piston is vaseline. Oil is too thin 
and it tends to work into the rubber hose, and 
even into the tire itself if too much is used. Vas¬ 
eline, on the other hand, clings to the leather 
and lasts a considerable time. If the leather 
becomes dry it does not hold air well, and pump¬ 
ing to high pressure becomes impossible, while 
the labor of pumping even to low pressure is 
greatly increased. 

Replacing Broken Ball. When replacing a 
broken ball in a ball bearing it is better to re¬ 
new the whole set, unless the new ball can be 
carefully gauged to be of the same size as the 
others. If this is not attended to, the new ball, 
having to bear more than its share of the 
weight, quickly succumbs. The greatest care 
should be taken, of course, to use grease free 
from grit, and to clean the balls and bearings 
before they are replaced. 

Cleaning Tops. Tops may be cleaned by us¬ 
ing gasoline, a little ivory soap and a brush. 
Sometimes, however, when cleaning with gaso¬ 
line the water-proofing quality of the materials 
may be destroyed. This can be restored by an 
application of paraffine. Dissolve the paraffine 
with gasoline and apply with a clean brush, the 
gasoline will carry the paraffine into the fabric 


The Automobile Handbook 


525 


and will evaporate, leaving the paraffine in the 
fabric. 

Useful Hints. At A, Fig. 251, is shown a 
simple tool found to be universally useful for 
wedging off magneto driving pinions, and other 
small members fitted to coned shaft ends, with 
or without key retention. This can be easily 
made from a large file, or any piece of steel of 
sufficient dimensions, depending upon the work 
to which it would be applied. The opening in 
the fork need not be more than three-quarters 
inch for the average magneto, the tines about 
two inches long, and three-eighths inch wide and 
taper from nothing to about one-quarter inch 
at the thickest part. Two of these are needed 
and are placed back of the gear, the tapered 
portion of one piece resting on that of the 
other, as shown. To remove the gear the ends 
are driven in toward the centre at the same 
time. This exerts a lifting effort, due to the 
wedge action of the tools immediately back of 
the pinion. The advantage of this method is 
that the shaft on which the gear is mounted is 
not subjected to any side strains, such as would 
result if attempts were made to drive off the 
gear by holding an S wrench back of the gear 
and driving against it with a hammer. When 
removing worn sprockets from the counter 
shaft in order to replace them with new ones, 
trouble may be experienced in loosening the 
nui especially if the rear wheels have been re¬ 
moved. In such cases the chain may be utilized 


526 


The Automobile Handbook 


to hold the sprocket in the manner shown at 
B, Fig. 251, by anchoring it to the axle with 
an S hook made of three-eighths inch cold rolled 
steel rod The sprocket will be firmly held and 
the nnt removed without difficulty. 

Although some grades of rubber hose are bet¬ 
ter than others, unless properly cared for even 
the best will deteriorate rapidly. Among the 
factors which make for rapid wear are careless 
stowage and abuse. The hose is left on the 
wash stand, cars are run over it, and when it 
has served its purpose, it is thrown in a heap 
and oil and grease accumulations soon work 
havoc with the rubber walls. A good rule to 
follow is to have a place for everything and 
everything in its place. It is not unusual to 
see a coil of hose carefully hung upon a nail, 
as shown at C, each coil having a sharp 
“kink” in it, both top and bottom, as indicated. 
This sharp bend tends to break the fabric walls, 
and the hose soon leaks. The proper way of 
hanging a hose is to use five or six wooden pegs 
arranged around an arc of a circle, as shown. 
Under these conditions the coils take a grad¬ 
ual curve, and do not assume a sharp angle as 
when but a single point of support is utilized. 
If the hose is one of some length a reel should 
be used. 

Often when fitting bushings and parts, and 
in general operations where reamers are used 
it is found that the tool will be just a trifle 
undersize, or that it is desirable to have the 


The Automobile Handbook 


527 


reamed hole just a little oversize. In such cases 
a simple expedient, as shown at D, Fig 251, will 
be found valuable. A small sheet of brass, or 
zinc is rolled in such a manner that it will fit 
between two of the cutting edges of the reamer. 
If the reamer is inserted with the roll of metal 
in place it will be evident that the reamer will 
be forced a trifle from the centre of the bore 
and the cutting edges of the reamer opposite 
the inserted metal roll will remove the metal. 
Very fine cuts should be taken, and the metal 
roll placed between different cutting teeth each 
time that the tool is used. In tapping out nuts 
it is often desirable to have the thread a little 
deeper than the standard, or to have the nut a 
loose fit on the bolt, as is sometimes necsesary 
when trying to place a machine screw nut on a 
carnage bolt. In this case a similar roll of 
metal may be placed between the cutting edges 
of the tap, as shown at E, Fig. 251. 

Solder. Silver solders are generally used for 
very fine work. They are very fusible, and 
non-corrosive. Hard spelter is used for steel 
and iron work, and soft spelter for brass work. 

When copper is soldered to iron or zinc, resin 
should be used, or if chloride of zinc is used for 
a flux, the joint should be washed afterwards 
to remove the acid. Un-annealed wires should 
be soldered at as low a temperature as possible. 
Solder, is always an alloy of other metals. It 
must not only be more fusible than the metal, or 
metals to be joined, but it must have some chem- 


528 


The Automobile Handbook 


ical affinity for them. Different kinds of solder 
are therefore employed for different purposes. 
It is called either hard or soft, according to its 
fusing point. 

Solders and spelters for use with different 
metals, and their proportional parts by weight 
are 

Solder for: 

Electrician’s use—1—Tin, 1—Lead. 

Gold—24—Gold, 2—Silver, 1—Copper. 
Patinum—1—Copper, 3—Silver. 

Plumber’s—Hard—1—Lead, 2—Tin. Soft— 
3—Lead, 1—Tin. 

Silver—Hard—1—Copper, 4—Silver. Soft— 
1—Brass, 2—Silver. 

Tin—Hard—2—Tin, 1—Lead. Soft—1—Tin, 
1—Lead. 

Spelter for: 

Fine brass work—8—Copper, 8—Zinc, 1^ 
Silver. 

Common brass—1—Copper, 1—Zinc. 

Cast iron—4—Hopper, 3—Zinc. 

Steel—3—Copper, 1—Zinc. 

Wrought iron—2—Copper, 1—Zinc. 

Fluxes for Soldering. Some good fluxes for 
soldering purposes are: 


Iron or steel.Borax or sal-ammoniac. 

Tinned Iron .Resin or chloride of zinc. 

Copper to iron .Resin. 

Iron to zinc .Chloride of zinc.* 

Galvanized iron .Mutton tallow or resin. 

Copper or brass .Sal-ammoniac or chloride of zinc. 

Lead .Mutton tallow. 

Block tin .Resin or "Sweet oil. 


♦Chloride of zinc is simply zinc dissolved in hydrochloric 
(muriatic) acid, until the acid is cut or killed. 











The Automobile Handbook 529 

Scratched Cylinder. The cylinder may be 
temporarily fixed by taking it to a first-class 
tinsmith and having the scratches filled with sil¬ 
ver solder. The soldered places must he then 
carefully scraped flush with the bore of the cyl¬ 
inder. The best way is to have the cylinder re- 
bored and the piston-rings re-turned. 

If the scratches are not too deep the cylinder 
can be rebored, and a new set of piston-rings 
made to fit the new bore. The limit to such an 
increase in bore is about one-sixteenth of an 
inch. 

If the damage to the cylinder walls has been 
comparatively slight, due to the conditions 
being recognized early, the engine should be 
disassembled and the surfaces thoroughly 
cleaned of any dirt or carbon. After reassem¬ 
bling, the full amount of lubricating oil should 
be put into the engine, and with the oil should 
be mixed an amount of graphite, in either the 
amphorous or flake form, proportioned to the 
kind being used and the body of the oil. Con¬ 
tinued use of graphite will tend to fill the 
small scratches in the metal. 

Garage—Cleaning Floors. A hot saturated 
solution of common washing soda will do very 
well. This can be made up in quantities and 
stored against future use. If this method is 
used, be sure to reheat it before using, the boil¬ 
ing point being about right. Since that will be 
too hot to apply with the hands, use any old 
broom or brush to “slosh’’ it around on the 


530 The Automobile Handbook 

floor. An equally good, if not better, solution to 
use for this purpose is trisulphate of sodium, 
marketed by several chemical companies, and 
sold at from four to five cents per pound at re¬ 
tail. This can be used cold and will not injure 
the most delicate hands; on the other hand, it 
will clean them very thoroughly, so that users 
of this solution use it for the hands as well as 
for the floors. This is strong, however, and 
may be used to remove paint. 

Protection From Fire. The recommenda¬ 
tions of the National Fire Protection Associa¬ 
tion pertaining to garages and their operation 
are as follows: No dynamo or gas engine should 
be permitted where gasoline is stored or han¬ 
dled; all exposed lights should be eliminated; 
cleaning*of acetylene lamps and removal or re¬ 
newing of carbide should be carried on outside 
of garage; the residue of acetylene lamps 
should never be cast on the floor* machines 
should have oil tanks emptied before being put 
in the repair shop; the use of extension electric 
wires is condemned, as they may cause fire; mo¬ 
tor testing should be done outside, for sparks 
might ignite the fumes of gasoline; storage 
tanks should be filled from outside of garage; 
all volatile oils should be stored in good, heavy 
tanks under ground, as far away from the 
building as possible; pipes for filling storage 
tanks should not pass through the garage in 
any way; a filling station should be twenty to 
thirty feet from the entrance to the garage, and 


The Automobile Handbook 531 

tanks of cars filled from there if it is necessary 
to fill them when the cars are inside of the gar¬ 
age; furthermore, the station should be fire¬ 
proof, and all cars should be brought to this 
point for filling; smoking and carrying of 
matches, or use thereof should be strictly pro¬ 
hibited; floors should be kept free of oil drip¬ 
pings, and pails of sand should be kept handy 
in proximity to gasoline. 

A garage of ordinary size should be equipped 
with at least four or five chemical fire extin¬ 
guishers, and these should be placed so that 
they may be quickly reached by any one in case 
of emergency. The stream from such an extin¬ 
guisher will smother a fire before it has done 
much damage if the flame can be reached within 
a minute or so of the time when it started. 
The chemicals usually used will not harm the 
finish of the car if the surfaces exposed are 
immediately washed in the usual way. Slight 
marring is of course preferable to destruction. 

Rheostat. A rheostat is a device for regulat¬ 
ing the flow of current in a closed electrical 
circuit, by introducing a series of graduated 
resistances into the circuit. 

Running Gear. A complete running gear in¬ 
cludes the frame, springs, wheels, motor, speed- 
change-gear, axles and the machinery of the 
car except the body. The French word, chassis, 
is sometimes used to designate a running gear, 

Secondary Current. The current which takes 
its rise in the fine wire of the induction coil, and 


532 The Automobile Handbook 

which flows through the wire to the spark plug, 
is induced in the fine wire by the sudden rever¬ 
sal of the magnetism of the iron core. 

This change of magnetism is caused by the 
sudden interruption of the primary current. 

Self-firing, Causes of. If the motor should 
continue to run after the switch has been 
opened, it is due to an insufficient supply of 
lubricating oil, causing the motor to overheat, 
or to the presence of soot or some projection in 
the combustion chamber becoming incandes¬ 
cent. It may also be due to lack of water or 
to the water circulation working poorly, caus¬ 
ing the motor to overheat. 

Shaft Drive. The principal advantages which 
may be advanced for the shaft drive are, absence 
of noise, convenience with which all the parts 
may be housed in oil and protection from 
dust. It is especially adapted for use upon cars 
carrying their engines in front, with the crank¬ 
shafts parallel with the length of the car, as the 
direction of the power shaft does not have to 
be changed until the rear axle is reached, and 
as the power must also pass through one set of 
bevel gears, it is more efficient. 

The principal disadvantages of the shaft 
drive are that it is difficult to repair; it is some¬ 
what more complicated; it has considerable 
end-thrust and it is claimed that it is harder on 
the tires. 

Soldering. The surfaces to be joined should 
be fitted to each other as accurately as possible 


The Automobile Handbook 


533 


and then thoroughly cleaned with a file, emery 
cloth or wire brush. The work should then be 
heated as hot as possible without danger of melt¬ 
ing, as this heating causes the solder to flow and 
secure a good hold on the surfaces. It is im¬ 
portant that the soldering iron be kept well 
heated during the work, otherwise the solder 
will only stick and will not join the surfaces. 

The end of the soldering copper should be 
well tinned by first cleaning it with a file or 
emery cloth while hot, then dipping into flux 
and rubbing the tip on a bar of solder until a 
space extending one-half inch back is covered 
with clean bright solder. The tinned end should 
not be placed directly in the heating flame. 

Sweating is a form of soldering in which the 
surfaces to be joined are first covered with a 
thin layer of solder. These surfaces are then 
placed in contact and heated to a point at which 
the solder melts and joins. Sweating makes a 
stronger joint than ordinary soldering. 

Spark Plugs. The trouble with motors mis¬ 
firing, is generally due to dirty spark plugs. 
This is caused by using too much cylinder oil, 
which, when subjected to the intense heat in the 
cylinder, turns to carbon. This carbon depos¬ 
its on the insulated porcelain and the body of 
the plug, and instead of the current jumping 
from the point in the body to the point in the 
porcelain and making a spark, it follows the 
easiest path, which is the carbon, and does not 
make a spark at the plug points at all. When 


534 


The Automobile Handbook 


this occurs the motor will misfire. The first thing 
to do when a motor misfires is to test the spark 
plug. Turn the motor until the battery circuit 
is closed. Unscrew the spark plug from the mo¬ 
tor, then reconnect the wire to it just the same 
as it was before. Lay the metal part of the 
plug body on the flywheel or some other un- 



A—Platinum point. 

B—Thread. 

C—Plug body. 

D—Bushing. 

E—Insulated terminal. 


Fig. 252 

F—Porcelain hushing. 
G—Expansion spring. 
H—Asbestos washer. 
J—Lock nuts. 

K—Assembly nut. 


painted part of the motor, being careful that 
the metal part of the plug body only touches 
the motor and that the porcelain part is clear. 
If the spark jumps in short jerks between the 
inner end of the porcelain and the interior of 
the plug body it is sooted, and needs cleaning. 












The Automobile Handbook 


535 


If it jumps at the points as it should do, the 
trouble is elsewhere; probably at the battery, 
loose connecting wires, or the vibrator of the 
coil is not properly adjusted. 



SPARK PLUGS 


Fig. 253 

To clean a spark plug properly use a 50 per 
cent solution of hydrochloric (muriatic) acid, 
washing the points of the plug with a tooth 
brush, occasionally dipping the plug into the 



SPARK PLUG 


Fig. 254 

acid. After cleaning the spark plug in this 
manner, rinse it in water^^. 

Spark Plugs—Construction of. Two spark 
plugs are shown in Figure 252, which, while dif¬ 
fering radically in their construction, effect the 
















536 


The Automobile Handbook 


same purpose, that of producing a spark or arc 
in the combustion chamber of the motor. The 
accompanying table and reference to Figure 
x 252, will fully explain the construction of the 
spark plugs. 

Cross-sections of four different forms of 
spark plugs are shown in Figure 253. All are 
constructed with a view to make the outside or 
extraneous path caused by sooting, as long as 







ij: 


H 

jii 


!j)4 

SPARK PLUG 




Fig. 255 


possible, so as to prevent if possible short-cir¬ 
cuiting of the plug from this cause. 

Figure 254 shows a form of spark plug in 
which two extra air-spaces are provided, one 
between the center rod or terminal and the 
porcelain bushing and the other between the 
porcelain bushing and the shell or body of the 
plug. 

The spark plug shown in Figure 255 has a 
closed chamber around, and over the center in¬ 
sulated rod or terminal; this chamber is a part 



































The Automobile Handbook 


537 


of the body of the plug and forms the other ter¬ 
minal of the plug. It acts as a small combus¬ 
tion chamber, and streams of fire are supposed 
to be thrown from the small openings in the 
chamber, when the arc or spark occurs therein. 


iex Jacross flats. 
—li- 


H—[ROOT Dt AM 
£03 MAX. 
.600 MIN. 


HEX.1 5 ACROSS FLAT' 

4 - 




<4-3*- 

-to 


s? * 

r VI 


t \ 


X-IQ PITCH 
U5S FORM OF THREAD 
-PITCH DIAM.— 
.639 MAX. 
£36 MIN. 
PCUTSIDE DIAM:—I 
£75 MAX. 
£72 MIN. 


SMALL HEX. 



|JS5 FORM OF THREAD I 
| -PITCH DIAM.-Hi 
.839 MAX. 

.636 MIN. 
fSlDE DW 
£75 MAX. 

£72 MIN. 

LARGE HEX 


ALL DIMENSIONS BELOW SHOULDER ARE 
IDENTICAL FOR BOTH SPARH B-UG SHELLS 

Fig. 256 

S. A. E. Standard Spark Plug 


Spark plugs of American manufacture are 
made with three different sizes of threads: One- 
half inch pipe-size, the actual outside diameter 
of which is .84 of an inch, with 14 threads ner 

























































538 


The Automobile Handbook 


inch. Seven-eighths of an inch diameter, with 
18 threads per inch, and .7 of an inch diameter, 
with 17 threads per inch. The last named one 
is the French, or Metric standard thread. 

Specific Gravity. In the absence of a proper 
instrument, the specific gravity of gasoline or 
any other liquid may be obtained as follows: 

Weigh a certain quantity of distilled water 
at 4 degrees Centigrade, or 39 1/3 degrees Fah¬ 
renheit. 

Weigh the same quantity of gasoline or other 
liquid under test. 

Divide the weight of the liquid by the weight 
of the water, and this will give the required 
specific gravity of the liquid. 

The specific gravities of various liquids are 
as follows: 


Alcohol at 15° C. . 

Acid, nitric . 

Acid, sulphuric . . . 
Ether at 15° C. . . . 

Naptha . 

Oil, linseed . 

Petroleum . 

Gasoline at 15° C. . 
Water, sea, at 4°.. 
Water, pure, at 4° 


. 0.794 

. 1.217 

. 1.841 

. 0.720 

. 0.848 

. 0.94 

. 0.878 

0.680 to 0.720 

. 1.026 

. 1.0 


The specific gravity of the electrolyte used 
in storage batteries is usually close to 1,250 
under ordinary conditions. This figure will 
reach 1.300 or 1.310 with a fully charged start¬ 
ing and lighting battery, and may fall as low 
as 1.100 with a battery that needs charging 
badly. 

The specific gravity of a storage battery 
should be tested while the battery is being 












The Automobile Handbook 539 

charged or immediately after the charge has 
been discontinued, never just after water has 
been added. 

To test the gravity, it is necessary to use a 
hydrometer made and graduated for this work, 
the instrument being preferably enclosed in a 
tube fitted with a bulb and nozzle and called a 
hydrometer syringe. With the filling caps re¬ 
moved from each cell of the battery, the bulb is 
compressed, the nozzle inserted into the cell and 
enough liquid drawn up to float the hydrom¬ 
eter. The marking on the hydrometer stem 
at which the surface of the liquid remains is 
the specific gravity of that cell. The gravity 
should be nearly the same in all cells with a 
good battery. The liquid should be returned 
to the cell from which it was drawn. 

Spring's. The length and number of leaves 
in the springs of motor cars of similar weight 
and power vary, and without any reason for so 
doing. The general use of pneumatic tires hides 
many imperfections in this respect as well as 
in others. Springs of insufficient strength are 
a source of great danger, and frequent exami¬ 
nation should be given to .them. Springs are 
not necessarily of insufficient strength because 
they appear to be light. Short springs are not 
desirable, as they are more liable to break than 
a longer spring, the deflection per unit of 
length being greater. Stiffness in short springs 
is usually avoided by lightness, which is likely 
to lead to breakage, especially when the hole 


540 


The Automobile Handbook 



Fig. 257 

Full Elliptic Spring, Scroll Ends 



Fig. 258 

Semi or Half-Elliptic Spring 



Fig. 259 

Three Quarter Elliptic Spring 



Fig. 260 

Fixed Cantilever Spring 



Fig. 261 

Three Quarter Floating Cantilever Spring 




The Automobile Handbook 


541 


for the bolt through the center of the spring is 
made larger than necessary. 

Springs—Dimensions of. In calculating the 
dimensions and elastic limit of springs for mo¬ 
tor-car use, the elastic limit must be carefully 
considered with regard to the dead, and maxi¬ 
mum loads to be carried by the car. The dead 
load is the weight of the car when at rest. The 
maximum load is the greatest weight that can 
possibly be carried with good spring action. 
The springs to retain their elasticity should 
have their ultimate strength far beyond their 
maximum load capacity. 

The old practice of fixing a uniform curva^ 
ture of the spring leaves frequently leads to 
breakages due to distortions set up at the 
spring perch. This tendency is now aborted by 
making the spring leaves in such a way that the 
curvature begins at points beyond the spring 
perch, so that the clamps when they are pulled 
into tight relation do not straighten out the 
plates. It is still the custom to use a leather 
pad on which to rest the springs, because 
thereby the coefficient of friction becomes that 
of leather, and creeping tendencies are as a con¬ 
sequence remote. There is also the question of 
the camber given to the respective spring plates. 
If the plates are all of the same thickness, they 
should all be curved to the same radius, for 
then the extreme fiber strain would be equal in 
all the plates for every alteration in camber in- 


542 


The Automobile Handbook 


cidental to the service they are placed to per¬ 
form. 

Springs—Testing and Material. The life of 
a spring is forecast by the maker thereof, al¬ 
most independently of the quality of the mate¬ 
rial. If the spring is limber, and it is so placed 
as to indicate spring play, just at the point of 
reversals of camber, the life will be shortened. 
The superior grades of materials will stand this 
abuse for a comparatively long time, but the 
dynamic life of steel, like the life of every other 
animated thing, is limited. Inferior materials, 
advantageously situated, might last far longer 
than the superior products working at a disad¬ 
vantage. The initial camber to give a spring, 
for a given static camber, is a problem for the 
springmaker. 

Fig. 262 shows three views of a given spring, 
under the conditions as follows: The spring 
under static load, indicating the static cam¬ 
ber; straightened out under load; in reverse 
camber, in a testing machine, to the limit before 
permanent set. 

It is worth while to study these three condi¬ 
tions in relation to springs, because they have 
to do with the life of the spring in service, and 
the easy riding qualities of the car due to spring 
action. It might be said in general that the 
greater the difference between the initial and 
the static camber, the more pronounced will be 
the easy riding qualities, and it might be said 
as well that the greater the initial camber, and 


The Automobile Handbook 


543 


the greater the possible reverse camber, the bet¬ 
ter will be the life of the springs, especially if 
we take into account that the spring action in 
service will be limited between the two points, 
as represented by the initial camber on the one 
hand and the condition', which means that the 
spring leaves will no more than straighten out 
in actual service. If the service conditions are 
such as to eliminate any reversal of camber, 



then it may be said the factor of safety will bt 
represented by the amount of the reverse cam¬ 
ber in a testing machine before permanent set. 

Springs—Care of. Springs should be exam¬ 
ined occasionally, and while often* overlooked, 
this seemingly trifling matter has a direct bear¬ 
ing upon the smooth, easy running of the car. 
Owing to the fact that the springs are exposed 
to the weather, rust is very likely to occur at 








544 


The Automobile Handbook 


this point, and to this unsuspected corrosion is 
often due the occasional “squeak.'’ Although 
many cars are provided with some means for 
lubricating the friction surfaces, many cars are 
not so well provided for and when rust makes 
its appearance along the joints there is a cry¬ 
ing need for oil. This may be conveniently 
applied by placing the jack between spring and 
frame, and slightly opening the leaves or plates. 
The toggles and links should also have a little 
oil occasionally and when about this work it is 
well to examine the nuts of the clips. These 
nuts are prone to work loose. 

TABLE 13 

SPRING WIDTH, EYE AND CLIP DIAMETER 

(S. A. E. Pleasure Car Standard) 

Car Weight Spring Load per Spring Eye Clip 
„ ■ Spring Width Diam. Diam. 

1,800 to 2,600 Front 500- 700 1 % 

Rear 600- 750 1% 

2,600 to 3,200 Front 600- 800 2 

Rear 700- 900 2 

3,200 to 4,000 Front 750-1,000 2% 

Rear 850-1,100 2% 

Over 4,000 Front Over 1,000 24 

Rear Over 1,100 2% 

Car weights are for cars empty, while loads per 
spring are for total loads of cars with passenger and 
equipment. 

Where rear springs take the drive or both 
drive and torque, % inch is added to the diam¬ 
eter of the eye at the driving end. Where rear 


% 1/2 

5 /s 1/2 

% 9/16 

% 9/16 

% 5/8 

% 5/8 

% 3/4 

% 3/4 


The Automobile Handbook 


545 


springs take the drive, the drive and torque or 
are underslung, 1/16 inch is added to the clip 
diameter. 

In Figure 263 are shown a number of forms 
for the leaf points used on springs. The five 
in the upper row and the two at the left of the 
lower row are the types most used. Reading 




Fig. 263 

S. A. E. Standard Spring Leaf Ends 


from left to right in the upper row, the points 
are named as follows: oval, round point, short 
French point, round end slot and bead, and 
ribbed. In the lower row, from left to right 
the names are: square point tapered, diamond 
point, egg shape and bevel, blunt end slot and 
bead, and French point. 








546 The Automobile Handbook 

Starting and Lighting Systems. 

Four principal types of engine starters have 
been used; the air starter, the mechanical 
starter, the acetylene starter and the electric 
starter. Beginning with the production of 1916 
cars, the electric starter is the only one found 
as standard equipment. 

Acetylene starters were used by many cars 
in 1913. This form admits acetylene gas from 
the lighting tank to the cylinder that is ready 
to fire through a distributor valve. The passage 
of an ignition spark caused by operating a but¬ 
ton on the dash fires the gas and the force of 
the explosion starts the engine. 

Mechanical starters are found in many forms. 
They consist of a mechanism through which the 
driver is enabled to turn the engine crankshaft 
through connections that lead to a handle or 
lever that may be reached from the seat. 

Compressed Air Starters. In a typical air- 
pressure system the motor is operated with 
compressed air until regular explosions take 
place in the’cylinders; the air supply is then 
shut off and the motor takes up its regular 
operations. 

The parts of this self-starter are as follows 
(see Fig. 264) : 1, a high-pressure, four-cylin¬ 
der air pump, for compressing air in a storage 
tank; 2, a pipe for carrying air from pump to 
storage tank; 3, a pipe which carries air from 


The Automobile Handbook 


54T 



- s (Jj ' ’*«' 

•V «f - > 

' 'S V'\ .' 

r? W 1 ? 

mm 
K ■ & 




vut m 

fi? !*? 

it 

3 * 

<.** 
a § 

/ft 

?5 


* 


Fig. 264—Chalmers Air Pressure Starting Mechanism 









































548 The Automobile Handbook 

tank to push valve on the dash; 4, a pipe which 
carries compressed air from the push valve to 
the “ distributor ’5, pipes through which air 
is carried from the distributor to the various 
cylinders; 6, poppet valves—one in each of the 
cylinders—by means of which compressed air 
from the distributor is admitted to the cylinder 
ready for the working stroke; 7, a pressure 
gauge on the dash, which keeps the operator 
informed of the amount of compressed air in 
the storage tank; and 8, a pump clutch, oper¬ 
ated by a foot pedal, which throws the gears 
of the air pump into mesh. 

The air pump in this system is driven by a 
silent drive chain from the water pump shaft, 
and operates only when the gears are thrown 
into mesh by pressing the pump clutch foot 
pedal. It is a simple device for compressing 
the air and delivers a steady flow to the storage 
tank. A pressure of 50 lbs. in the tank will 
start the motor under ordinary conditions, but 
it is advisable to keep the pressure at about 
150 lbs. 

The storage tank is carried beneath the body 
of the car and is tested for a pressure of 600 
lbs. to the square inch. 

The dash push valve opens the air line from 
the storage tank to the distributor and simul¬ 
taneously opens the cylinder valves so that air 
coming from the distributor through the pipes 
shown in Fig. 264 has ready access to the cyl¬ 
inders. When the foot is removed from the 


The Automobile Handbook 549 

dash button, both the escapement valve and 
the cylinder valves are closed automatically 
and the compressed-air starter is shut off from 
the motor. 

The distributor sends charges of compressed 
air into the cylinders ready for the working 
stroke, in their order of firing. It is geared 
to the pump and magneto shaft and positively 
timed for feeding air. 

This type of self-starter is also used for the 
purpose of inflating tires by means of a special 
shut-off valve and hose. 

The principle of compressed-air starters is to 
admit air under 50 to 150 lbs. pressure from a 
generous reservoir directly to the motor cylin¬ 
ders at the beginning of each expansion stroke. 
This operates the motor without affecting the 
mixture in the cylinders. When running under 
air pressure the admission of the compressed 
air at almost the moment of the spark operates 
the same as an ignition, causing a rise of pres¬ 
sure in the cylinder. After it has performed 
its work this pressure is released by the ex¬ 
haust valve in the same manner as the burned 
gases are released when the motor is running 
under its own power. 


550 


The Automobile Handbook 


Allis-Chalmers Equipment. The most com¬ 
monly used type of Allis-Chalmers equipment 
makes use of a combined motor-dynamo, Fig. 



Fig. 265 

Allis-Chalmers Motor-Dynamo. E, Commutator. 
F, Brush Holder. G, Brush Connection. H, 
Brush Connection. 

265, operating at six volts pressure for starting, 
charging and lighting. In addition to the motor- 
dynamo, the system includes the battery, a start* 






The Automobile Handbook 


551 


ing switch and a separately mounted combined 
cut-out and regulator. 

Pushing the starting switch connects the bat¬ 
tery with the motor-dynamo, which then oper¬ 
ates as a motor to crank the engine to which it 
is mechanically connected. The switch is then 
released after the engine fires. The motor- 
dynamo speeds up with the engine and, when 
it reaches a certain predetermined speed, is auto¬ 
matically connected to the battery and the light¬ 
ing system by means of the cut-out. If the 
lights are burning, part of the current is used 
in lighting, the surplus going to charge the 
battery. When the engine slows down below the 
charging speed, the cut-out opens the circuit be¬ 
tween the generator and battery. 

By removing the cover band, the commutator 
may be examined. When in good condition it 
will show a glaze and will be dark brown in 
color. If the commutator appears dirty or 
greasy it should be wiped off with a clean cloth 
free from lint, slightly moistened with oil. 

Do not disturb the brushes so long as the 
motor-generator appears to be operating prop¬ 
erly. They should make good contact with the 
commutator and slide smoothly in the brush 
holders. 

The purpose of the combined cut-out and reg¬ 
ulator is .to connect the generator to the battery 
when its voltage equals that of the battery, and 
to maintain a practically constant charging cur¬ 
rent with the widely varying speeds of the en- 


552 The Automobile Handbook 

gine. It also disconnects tlie battery when the 
motor-generator voltage falls below that of the 
battery, preventing the battery from discharg¬ 
ing. 

The regulator-cutout consists of a compound 
wound electromagnet with two armatures, one 
of which serves as the cut-out while the other 
regulates the charging current. The shunt reg¬ 
ulator winding is always connected across the 
generator terminals. When the generator volt¬ 
age is sufficient for charging, the electromagnet 
attracts the armature, closing the circuit through 
the series coil of the regulator of the battery. 
The current flowing in the series coil then as¬ 
sists the shunt coil to hold the contacts to¬ 
gether. With an increase in generator speed, 
the charging current will increase, strengthen¬ 
ing the regulator electromagnet. At a certain 
critical point the second armature will vibrate, 
alternately cutting a resistance in and out of 
the generator field circuit, which will reduce 
the charging current by lowering the generated 
voltage. When the generator speed, and conse¬ 
quently the voltage, drops below charging value 
the reverse battery current flowing in the series 
winding neutralizes the shunt winding, releas¬ 
ing the armature and thus opening the circuit 
before the battery can discharge. 

The internal connections and mechanism of 
the regulator-cutout are shown in the diagram, 
Fig. 266. 

The regulator is provided with a fuse to pro- 


Fig. 266 

Allis-Chalmers Motor-Dynamo Internal Connections 


The Automobile Handbook 553 












































































554 


The Automobile Handbook 


tect the system from excessive charging current, 
or an improper discharge through the starter, 
in case the regulator should not function prop¬ 
erly. This fuse has a capacity of 45 amperes 
and carries the shunt field current as well as 
the battery charging current." The fuse, which 
is made of an especially hard alloy to withstand 
the high temperature near the engine, should 
always be replaced by one of the same make. 
If several fuses are blown within a short time, 
the regulator is probably out of order and 
should be replaced. This fuse does not protect 
the lighting and horn circuits. 

To prove whether the motor-dynamo is charg¬ 
ing the battery or not, remove the wire from 
the “BAT.-f” terminal of the regulator and 
insert an ammeter between this terminal and 
the wire, with the positive terminal of the meter 
connected to the terminal of the regulator. With 
the engine running at about 60 revolutions per 
minute or higher, the meter should show a charg¬ 
ing current of 10 to 18 amperes. If the meter 
shows no current, the motor-dynamo is either 
not developing any voltage or there is an open 
circuit in the charging line. To determine 
whether the motor-dynamo is developing any volt¬ 
age, open the circuit at ammeter and then 
remove the wire from the “F L D” terminal 
of the regulator. With the engine still running 
as above, there should be quite a flash on re¬ 
moving the wire from the “F L D” terminal of 
the regulator. All these tests are to be made 


The Automobile Handbook 555 

with a good fuse in place on the regulator. If 
no flash is obtained on removing the wire from 
the “F L D” terminal, hold the wire on the fuse 
clip for a few seconds and note whether there 
is a flash on removing it. A flash here and none 
from the “F L D” terminal indicates a fault in 
the regulator. No flash from the fuse clip indi¬ 
cates a fault in the motor-generator. It is as¬ 
sumed here that the connections between the 
regulator and the motor-dynamo have been ex¬ 
amined and found correct and sound. 

If the motor-dynamo develops its voltage but 
still does not charge the battery, the fault is 
either in the regulator or the auxiliary contact 
of the starting switch. This can be located by 
connecting up the ammeter again as before, and 
with the engine still running hold a wire pumper 
in the hands and first connect the “DYN+” 
terminal of.the regulator to the “BAT-f-” ter¬ 
minal. If the battery now charges, the fault is 
in the regulator. If no result is obtained, con¬ 
nect “BAT+” terminal of the regulator to the 
positive terminal of the battery. The charging 
of the battery now would indicate that the fault 
was in the starting switch. 

The motor-dynamo should not be run with the 
charging circuit open, except for a minute or 
'two at a time in making tests and not at all at 
very high speeds, as it would damage both the 
motor-dvnamo and the regulator, and also the 
lights if turned on. If it is necessary to operate 
the car with the battery removed or with the 


556 


The Automobile Handbook 


battery circuit open in any way, so that ii can¬ 
not charge, the fuse must be removed from its 
place on the regulator. 

Auto-Lite Equipment. These systems con¬ 
sist of separate unit dynamos and starting 
motors operating with a six-volt pressure in- all 



Fig. 267 

Auto-Lite Dynamo With Permanent Field Magnets 
and Clutch Governor 

cases. The first models were of the permanent 
magnet type, that is to say, the dynamo field 
consisted of six powerful steel magnets without 
the usual coils, Fig. 267. These magnets were 
of the inverted U, or horseshoe, type, and under¬ 
neath the arch thus formed was mounted an 
electromagnetic cut-out which closes the charg¬ 
ing circuit whenever the dynamo voltage is suffi- 






The Automobile Handbook 557 

eiently high to charge the battery. This part of 
the mechanism may be exposed by removing the 
brush wires and taking out the plate that car¬ 
ries the positive and negative dynamo terminals. 

This permanent magnet dynamo is driven 
from the engine by silent chain, but between 
the chain sprocket and the dynamo armature 
shaft is a form of slipping clutch governor con¬ 
tained in the drum seen at the left hand end of 
Fig. 267. The shell of this drum has its driving 
connection to the shaft by means of two shoes 
that are pressed outward by springs. Two 
weights are carried at or near the ends of corre¬ 
sponding arms inside of the drum, and when 
the armature shaft has reached a certain pre¬ 
determined speed the centrifugal action of the 
weights overcomes the tension of the springs and 
the shoes release their hold on the shell. By 
thus preventing an armature speed above the 
desired maximum, the voltage and output of 
.the dynamo is held at a point suitable for bat¬ 
tery charging. 

A later form of Auto-Lite dynamo is shown 
in Fig. 268. This model retains the inverted U 
form of field magnet cores, but around the top 
of the magnet arch is placed a field coil housing 
and in this housing is a shunt and a reversed 
series field winding. The shunt field winding 
is attached between the brushes in the usual 
way, and the entire dynamo output passes out 
through the reversed series winding. This 
series winding being placed in such a way that 


558 


The Automobile Handbook 


it opposes the action of the shunt, dynamo out¬ 
put above a certain point is made to overcome 
the field magnetism to such an extent that the 
amperage shows no further rise. The two 
dynamo terminals are seen on the front of the 
field housing and with this machine the electro¬ 
magnetic cut-out is separately mounted, usually 
on the dash of the car. 



Fig. 268 

Auto-Lite Dynamo With Electromagnetic Fields 

A third type of Auto-Lite dynamo is shown in 
Fig. 269. This machine is fully enclosed and 
has its fields placed above and below the arma¬ 
ture. The field windings and regulation of out¬ 
put by means of the reversed series coil is the 







The Automobile Handbook 


559 


same as in the type just described. The brushes 
and commutator may be exposed by removing 
the plate A. 

Bijur Equipment. These systems are made 
in three distinct forms, two being six-volt sepa¬ 
rate unit dynamo and starting motor types, 
while the third is a combined motor-dynamo op¬ 
erating at twelve volts for both charging and 
starting. 



Auto-Lite Fully Enclosed Dynamo. 

One of the six-volt systems makes use of a 
straight shunt-wound dynamo having a com¬ 
bined regulator and cut-out mounted in an 
aluminum housing on top of the dynamo case. 
Connected in series with the shunt winding is a 
coil of high resistance wire which is automatic¬ 
ally inserted in the shunt field circuit by the 
regulator, this action keeping the yoltage con¬ 
stant. The regulator consists of an electro¬ 
magnet with its winding shunted across the 













560 The Automobile Handbook 

brushes, so that current always flows around 
the magnet when the dynamo runs, also the 
regulator contacts which are connected to carry 
the shunt field current around the resistance 
coil when they are closed. As the dynamo volt¬ 
age rises, the magnet pulls the armature against 
the small spring and opens the contacts. The 
shunt field current then flows through the re¬ 
sistance and is so reduced that the field strength 
and voltage immediately fall. The low voltage 
reduces the strength of the electromagnet and 
the spring again closes the contacts, allowing the 
field current to avoid the resistance coil and 
raise the voltage. The regulator contacts vibrate 
this way at the rate of about 100 times a second 
and this holds the voltage at a point determined 
by the strength of the regulator spring or its 
tension. 

The cut-out is electromagnetic with two wind¬ 
ings and is carried in the same case with the 
regulator, this case being on top of the dynamo. 
All connections between dynamo, regulator and 
cut-out are made between the regulator housing 
and dynamo case and are not exposed. Two 
wires only come from the dynamo, one positive 
and one negative. 

The dynamo wires end in a brass plug on one 
end of the regulator case. This plug may be 
rotated in its socket so that it makes part of a 
turn one way or the other. Turning this plug 
as far toward the engine as it will go makes one 
wire positive and the other negative, and turn- 


The Automobile Handbook 


561 


ing it as far from the engine as it will go re¬ 
verses this polarity. This reversal should be 
made every 500 miles, being sure that the plug 
is turned as far as it will go so that it locks in 
place. This action reverses the polarity of the 
dynamo and prevents pitting of the contacts. 



Bijur Wiring Diagram for Voltage Control System 

After adjustments are made the regulator box 
is sealed at the factory and the maker’s instruc¬ 
tions say not to open it. The entire box may 
be removed from the dynamo by unscrewing the 
small milled nut on top, the connections between 
the cases being made with split pins. Lights 
and starter will run from the battery while the 
regulator is returned to the makers for repairs. 
A complete wiring diagram for this form of 
Bijur apparatus is shown in Fig. 270. 









































U4*Tih« ftwrTC* 


562 


The Automobile Handbook 


In Fig. 271 is shown the application of an¬ 
other form of six-volt separate unit system. 



T’his dynamo has no controller box as has the 
one just described, but the shunt field winding 


Fig. 271 

Bijur Wiring Diagram for Third Brush Dynamo 



































































The Automobile Handbook 563 

is connected to an additional brush bearing on 
the dynamo commutator. This brush is for the 
purpose of limiting the dynamo amperage and 
is so placed in relation to the main brushes that 
the current passing into it, and thereby into the 
shunt field, diminishes with increase of speed. 
The normal tendency of the output to increase 
with the speed of rotation is therefore counter¬ 
acted and a safe maximum is maintained. This 
is the form of regulation known as “third 
brush.” 

The electromagnetic cut-out for this system 
is mounted inside of the brush and commutator 
end of the dynamo case. This end of the ma¬ 
chine is closed by a removable brass band, and 
through the openings left with this band re¬ 
moved the working parts of the machine may be 
inspected. Mounted on the outside of the dy¬ 
namo case, and connected in series with the field 
windings, is a small fuse which will blow out 
whenever the current passing through the fields 
becomes excessive. This fuse will protect the 
dynamo in case of a broken circuit between 
dynamo and battery or lamp lines. 

Separate starting motors of Bijur make may 
drive to the engine through an overrunning 
clutch, through direct acting spur gears or by 
means of a Bendix screw. With the Bendix 
screw, a single contact starting switch is used 
which sends the full battery current to the motor 
when the switch is closed. With the spur gear 
v J rive, the starter switch makes a preliminary 


564 The Automobile Handbook 

contact through a resistance coil and continued 
movement of the switch pedal and plunger 
closes the contacts that short circuit the resist¬ 
ance and send the full battery current through 
the motor. The same operation that meshes the 
starting gears moves the switch plunger. 

Bijur motor-dynamos operate at twelve volts 
and have their output controlled by the “ third 
brush’’ system as explained for the type just 
described. Drive is direct to the engine crank¬ 
shaft through a silent chain. No cut-out is used, 
but when the motor-dynamo is connected to the 
battery by means of the starting switch, the 
switch is allowed to remain closed and the in¬ 
creasing speed of the unit when driven from 
the engine causes the voltage as a dynamo to 
rise to a point that recharges the battery. When 
the car is operated at a speed below about ten 
miles an hour, the dynamo voltage falls below 
that of a battery and the unit again becomes 
a starting motor. A neutral position is pro¬ 
vided on the starting switch for use when the 
car is being driven at low speeds or when the 
engine is idling. With the switch in this posi¬ 
tion the motor dynamo is disconnected and bat¬ 
tery discharge is prevented. 

Bosch Equipment. The dynamo is shown 
in Fig. 272 and is used in connection with a 
starting motor of the Rushmore type and having 
the Rushmore form of drive to .the flywheel. 

The dynamo is a separate unit, shunt wound, 
delivering 12 volts with a maximum output of 


The Automobile Handbook 565 

8 to 10 amperes at high car speeds with a par¬ 
tially discharged battery. 

'A box mounted on the dash carries a volt- 
ammeter, voltage regulator, cut-out, lighting and 
ignition switches and fuses. A small lever is 
moved to cause the meter to show either volts 
or amperes on the same meter. 



Fig. 272 
Bosch Dynamo 

Regulation acts to maintain a steady voltage. 
The regulator consists of a small cylinder of 
carbon particles with one end of the shunt field 
winding connected to one end of the carbon pile 
and the corresponding dynamo brush connected 
to the other end of the carbon. The shunt field 
current thus passes through the carbon. The 
carbon particles are held tightly compressed by 
a plunger fitting inside the cylinder with a coil 
spring holding the plunger down. Under this 
condition the resistance of the carbon is very 
low and allows practically the whole of the 



566 The Automobile Handbook 

shunt field current to pass without interruption. 
An electromagnet forms part of the regulator 
and is connected in shunt across the dynamo 
brushes so that its strength increases with the 
rise in voltage. This electromagnet acts to pull 
up on the plunger against the action of the 
spring, and as the voltage rises the pressure on 
the carbon is lessened in this way and the re¬ 
sistance of the carbon pile increases rapidly as 
the particles are loosened. This resistance in 
the field lowers the voltage and output. 

An electromagnetic cut-out is carried in the 
dash unit housing with the voltage regulator. 
These systems make use of the single wire, 
ground return method of wiring. The start¬ 
ing cable is, however, covered with a copper 
sheath that assists in carrying the return cur¬ 
rent to the battery. 

Delco Equipment. A majority of Delco 
applications have been of the motor-dynamo 
type, this method being departed from for the 
first time on some of the applications made on 
1916 cars. The first Delco system to be used 
consisted of a motor-dynamo that operated as 
a starter at 24 volts and charged to six volts 
for lighting and battery charging. The bat¬ 
tery for this system consists of twelve cells 
divided into four sections of three cells each. 
By means of a two position multiple contact 
knife switch carried in the battery box, these 
sections were placed in series for starting and 
in parallel for lighting and charging. The 


The Automobile Handbook 56*f 

complete charging circuit diagram is shown in 
Fig. 273. 

The battery charge is controlled by a form 
of wattmeter, called an ampere-hour meter. 
Current flowing into the battery causes this 
meter to revolve in one direction and current 



Fig. 273 

Charging Circuit of Delco 6-24 Volt System 


flowing out of the battery causes it to revolve 
in the opposite direction. After a certain flow 
has entered the battery, the meter has moved to 
such a position that a resistance is inserted in 
the shunt field winding of the dynamo and the 
rate of charge is thereby reduced. Further 







































































568 


The Automobile Handbook 

















































































































































The Automobile Handbook 569 

movement of the meter in the same direction 
opens the shunt field current and further bat¬ 
tery charge is prevented. Withdrawal of cur¬ 
rent causes the meter to reverse this movement 
and the field circuit is first closed through the 
resistance and the resistance is then cut out 
entirely, allowing a resumption of full battery 
charge. 

Fig. 274 shows the complete circuit diagram 
for this system. The magnetic latch is for the 
purpose of allowing the driver to close the start¬ 
ing switch and mesh the motor gears with the 
flywheel when the clutch pedal is depressed. By 
means of a small push button, usually on the 
heel board, the latch magnet is energized and 
the latch itself connects the starting gearing 
with the- clutch pedal. Depression of the 
pedal then causes starting action as described. 
The application of this system on a car, with 
external wiring shown, is seen in Fig. 275. 

A form of Delco motor-dynamo having two 
separate commutators and two sets of brushes 
is shown in Fig. 276. One of these commuta¬ 
tors is for the dynamo generating action, while 
the other is for starting. 

When the unit is generating current for 
charging the battery, for lights and ignition, 
it is a simple shunt wound generator. It is 
driven from the engine by an extension of the 
pump shaft. The generator is driven at one 
and one-half crankshaft speed, and in order 
to compensate for the higher ratio when the 


570 The Automobile Handbook 


























































































































































































The Automobile Handbook 571 



Pig. 276 

Delco Motor-Dynamo With Starter Switch Mounted 
Above Flywheel Drive Gearing. A, Oil Hole. 
B, Oil Hole. C, Grease Cup. D, Gear Shift 
Yoke. E, Switch Operating Rod. F, Switch 
Spring. G, Flywheel Gear. H, Motor Pinion 
Gear. I, Clutch Shaft. J, Shift Yoke Rod. K, 
Tripping Collar. L, Contact Block Latch. M» 
Contact Block. 







































































572 


The Automobile Handbook 



Fig. 277 

Delco “Junior” Motor-Dynamo 
























































The Automobile Handbook 


573 


unit is in starting relation to the engine, a sec¬ 
ond one-way clutch is provided adjacent to the 
forward housing. This clutch permits the arma¬ 
ture to run ahead of the driving shaft during 
the cranking operation. 

Fig. 277 illustrates the Delco * ‘Junior’ * 
motor-dynamo and the starting switch is shown 



Delco Starting Switch 

in Fig. 278. These units cannot well be shown 
in their actual locations and are therefore shown 
separate. Referring to Figs. 277 and 278, the 
yoke H fits into the collar I which is pinned to 
the rod D. The movement of the rod from the 
starter pedal operates the gearing and the 
starting switch. 



















574 The Automobile Handbook 

When the starting pedal is pushed down it 
pulls back the rod D and closes the contact E, 
which completes the circuit between the battery 
and dynamo armature. The closing of the cir¬ 
cuit causes the armature to revolve slowly so 
that the gear J will mesh with the motor pinion 
as it slides along on its shaft. As the starting 
pedal is pushed further down it continues to 
pull the rod D, which opens the contact F, 
breaking the circuit between the battery and 
dynamo armature. This action of the rod at 
the same time causes the motor brush switch to 
drop onto the motor commutator, and the train 
of gears to slide on its shaft until in mesh with 
the motor pinion and the teeth on the flywheel. 

The motor brush dropping on the commuta¬ 
tor causes the circuit to be closed between the 
storage battery and the motor armature, which 
causes the motor to crank over the engine. 

When the starting lever is released the motor 
switch brush is raised from the motor commu¬ 
tator and the train of gears is thrown out of 
mesh, when the contacts F will automatically 
close. 

If the speed of the motor generator is above 
350 revolutions per minute, the cut-out relay, 
Fig. 279, will close the circuit between the stor¬ 
age battery and motor generator, thus permit¬ 
ting the generator to charge the storage bat¬ 
tery. If the speed of the motor generator is less 
than 350 revolutions per minute, the cut-out 
relay will remain open and all current for 


The Automobile Handbook 


575 


ignition and lights, if they are in use, will coine 
from the storage battery. 

Oil is conveyed to the ball bearings through 
oil cup B and the small hole A in the front end 
cover. This hole is made accessible by remov¬ 
ing the upper front end cover. At the time 4 
or 5 drops of light oil are put in the oil cup 
B and the hole A, the grease cup C should be 



6 


A 


Fig. 279 

Delco Reverse Current Cut-out 

given 1 or 2 turns or replenished if empty. 

The cut-out relay, Fig. 279, is located in the 
rear end housing of the generator. This instru¬ 
ment closes the circuit between the generate 


























576 The Automobile Handbook 

and the storage battery when the generator 
voltage is high enough to charge the storage 
battery. It also opens the circuit as the gener¬ 
ator slows down and its voltage becomes less 
than that of the storage battery, thus prevent¬ 
ing the battery from discharging back through 
the generator. The cut-out relay is an electro¬ 
magnet with a compound winding. The voltage 
coil or fine wire winding is connected directly 
across the terminals of the generator. The cur¬ 
rent coil, or coarse wire winding, is in series 
with the circuit between the generator and the 
storage battery, and the circuit is opened and 
closed at the contacts A. "When the engine is 
started, the generator voltage builds up and 
when it reaches about six volts a current pass¬ 
ing through the voltage winding produces 
enough magnetism to overcome the tension of 
the spring B, attracting the magnet armature 
C to core D, which closes the contacts A. These 
contacts close the circuit between the generator 
and storage battery. The current flowing 
through the coarse wire winding increases the 
pull on the armature and gives a good contact 
of low resistance at the contact points. 

Delco systems used during 1915 consist of sin¬ 
gle armature motor-dynamos, one application of 
which is shown in Fig. 280. The armature car¬ 
ries two commutators, one on each end or both 
on the front end, the rear end commutator be¬ 
ing for the starting motor action. 

Two separate field coils are used; a shunt for 


Fig. 280 Delco Starting and Lighting System, 1915 Type 
With Governor Control for Amperage 


The Automobile Handbook 


577 



HORN BUTTON 











































578 The Automobile Handbook 

the dynamo action and a series for the starting 
motor action. These coils are both on the same 
field magnet core and have separate terminals. 

The drive as a dynamo is from the' rear ex¬ 
tension of the pump shaft through a roller over¬ 
running clutch which releases when the arma¬ 
ture turns at high speed as a starting motor. 

The starting motor drive is through a pinion 
on the rear end of the armature shaft to a ring 
gear on the flywheel. Two gears, fastened to¬ 
gether, are free to rotate as a pair on an auxil¬ 
iary shaft, the gears being slid along this shaft 
by a yoke connected to the starting pedal until 
one is in mesh with the armature shaft pinion 
and the other with the flywheel gear, complet¬ 
ing the drive connection. A roller clutch is in¬ 
corporated in the front one of the pair of slid¬ 
ing gears, this clutch releasing while the arma¬ 
ture is being driven as a dynamo. 

Starting switch action is secured by normally 
holding one of the motor commutator brushes 
away from the commutator by means of a rod 
connected to the starting lever or pedal. "When 
the lever or pedal is moved this rod is drawn 
back so that the brush drops onto the commu¬ 
tator under the action of its spring, completing 
the circuit from the battery through the series 
winding and armature. This rod is fastened to 
the sliding gears so that they must be in mesh 
before the brush can drop. 

The dynamo brush that is grounded com¬ 
pletes its connection to ground through a pur 


The Automobile Handbook 


579 


of contacts, one stationary and one movable, 
Fig. 281. The movable contact is attached to 
an arm on the movable starter brush in such a 



Commutator End of Delco Governor Controlled 
Motor-Dynamo 


way that the contacts open as the starter brush 
drops onto the commutator. This prevents 
dynamo action while the armature is acting to 
start the engine. 




















580 


The Automobile Handbook 


No fuses are used, but there is a magnetic 
circuit breaker, the electromagnet of which acts 
to open the contacts from the battery and dy- 

AUTOMATIC REGULATING 



Fig. 282 


Governor and Overrunning Clutch Mechanism of 
Delco Motor-Dynamo 

namo to the lamp and car wiring when 25 am¬ 
peres flow. After the circuit breaker opens the 
contacts continue to vibrate open and closed if 



































The Automobile Handbook 581 

there is a flow amounting to five amperes. The 
circuit breaker will not stay closed until the 
ground or short circuit that is causing the leak 
of current has been removed. The spring of 
this current breaker should not be adjusted in 
any way as it is a safety device. 

Delco systems may have any one of three dif¬ 
ferent systems for regulating the dynamo out¬ 
put. One type consists of a differential or buck¬ 
ing coil carried on the field magnets and con¬ 
nected in series with the main line from the 
dynamo brush to the dash switch unit. 

Another method makes use of a coil of resist¬ 
ance wire carried on a spool in the front end of 
the dynamo case on the right hand side, Fig. 
282. One end of the shunt field winding is 
grounded through this resistance coil so that 
the field current would have to pass through 
the coil. This high resistance would allow but 
little flow and would weaken the field to such 
a point that the output would be very low. 
When the dynamo is running at low speeds the 
field current, after passing to the lower end of 
the resistance coil, goes to the ground through 
an arm making contact with the coil. This arm 
carries a contact which slides up and down on 
the resistance coil, the arm being moved by a 
centrifugal governor attached to the ignition 
distributer shaft. As the dynamo speed in~ 
creases, the governor weights cause the movable 
arm to raise so that its contact is farther from 
the bottom of the resistance coil, and the field 


582 


The Automobile .Handbook 


current must consequently flow through a great¬ 
er length of resistance wire before reaching the 
contact on the arm and passing to the ground. 
This greater resistance in the shunt field circuit 
allows less current to flow and by thus weak¬ 
ening the field cuts down the dynamo output 
at high speeds. 

The third system of regulation also causes 
the shunt field current to pass to the ground 
through a coil of resistance wire. This resist¬ 
ance coil is wound on a spool and the spool is 
carried at one end of a rod, the other end of the 
rod forming the plunger of a solenoid coil. The 
strength of this solenoid increases with the volt¬ 
age, being connected in shunt with the brushes. 
Increased strength of the solenoid pulls the 
plunger farther into the coil. This solenoid coil 
is in the upper end of a cylindrical housing, 
and the resistance coil is carried below the sole¬ 
noid. The plunger and resistance are normally 
in a low position but are raised by the solenoid 
action. In the low position the resistance coil 
dips into a well partly full of mercury so that 
the shunt field current does not have to pass 
through all the resistance wire but passes into 
the mercury and to the ground from a contact 
fastened to the mercury well. As the voltage 
rises the solenoid becomes stronger, lifting the 
plunger and pulling the resistance coil up out 
of the mercury well so that the shunt field cur¬ 
rent must flow through a greater length of re¬ 
sistance wire before reaching the ground. This 


The Automobile Handbook 583 

added resistance allows less current to flow 
through the shunt field and consequently lowers 
the field strength and the output of the dynamo. 

Delco systems use either of two methods of 
reverse current cut-out. One type comprises 
a dash switch with five buttons. The three left- 
hand buttons are for the lights, the two right- 
hand being for the ignition. The button on the 
extreme right is for the storage battery ignition, 
the one next to it being for the dry cells. Each 
of these buttons carries two contacts inside the 
switch, one completing the ignition circuit and 
the other completing the charging circuit. 
When the engine is to be started either of the 
ignition switches is pulled out. The current 
then passes from the battery to contact (1) on 
the switch, through the inner connection of 
either dry cell (Bat.) or storage battery (Mag.) 
switch and out of terminal (6) to the shunt 
dynamo winding and armature brushes. This 
causes the dynamo parts to act as a motor of 
very low power and the armature revolves 
slowly so that the starting gears can be meshed. 
As soon as the gears are meshed the motor 
brush drops onto its commutator and completes 
the starting circuit while breaking the dynamo 
circuit as described before. The battery cur¬ 
rent will then cease to flow through terminal 
(6) but will flow through the circuit breaker, 
whose points are held closed by a spring, and 
through the other connection on the switch but¬ 
ton plunger, out through terminal (7) and to 


584 


TJie Automobile Handbook 


o 



\ 


Pig. 283 

Delco 1916 Motor-Dynamo With Third Brush Control 









































































































































The Automobile Handbook 585 

the ignition coil. If the “Bat” button is pulled 
out the dry cell current comes into terminal 
(2) and out through (7) to the ignition coil. 
When the engine has been started and the dy¬ 
namo generates a voltage greater than the bat¬ 
tery, current will flow from the dynamo through 
the differential winding (if one is used) into 
terminal (6), through the inner contacts of the 
switch and out through (1) to the battery. If 
the ignition switches are left closed with the 
engine idle the battery will discharge through 
the switch contacts and dynamo parts, these 
switches acting as the cut-out with the dynamo 
and engine idle. 

The construction of Delco apparatus used 
during 1916 differs from that already described 
in one important particular. The output of 
the dynamo when charging the battery is con¬ 
trolled by the “third brush” principle. 

One of the applications is shown in Fig. 283 
and it will be noted that the armature and field 
location, starting drive and ignition mechanism 
is similar to the forms previously used. The 
brush position is shown in Fig. 284. The action 
is explained as follows: The full voltage is ob¬ 
tained between the large brushes and the volt¬ 
age between the left hand large brush and the 
small regulating brush is less than the full 
pressure. This reduced voltage is applied to 
the field coils. With the armature rotating, the 
magnetic field is twisted out of its normal path 
between the pole pieces, the degree of deflection 


586 The Automobile Handbook 

being in direct ratio to the increase of speed. 
This deflection causes the magnetic flow to be- 



Fig. 284 

Brush Mechanism of Delco Motor-Dynamo 


come weaker at the points on the pole pieces 
that affect the flow into the “third brush’’ and 
this weakened field current compensates for 
the higher output that would otherwise be 
caused by increase of speed. Fig. 285 shows 
the starting motor end of this same machine. 



















The Automobile Handbook 587 

Another application of the third brush dy¬ 
namo does not make use of the motor-dynamo 



Fig. 285 

Motor Brush Switch Connections of Delco Motor- 
Dynamo 


combination, but uses a separate series wound 
motor driving to the flywheel through a Bendix 


screw. 




















588 


The Automobile Handbook 


Dyneto and Entz Equipment. These in¬ 
stallations make use of a combined motor-dy¬ 
namo operating with twelve volts in some cases 
and with eighteen in others. A compound field 
winding is used, series and shunt coils acting 



Fig. 286 

Five Terminal Dyneto-Entz Motor-Dynamo 


together in starting and forming a reversed 
series controlled machine in generating. The 
reversal of the direction of flow through the 
series field while generating causes this winding 
to oppose the shunt winding at high armature 
speeds and the dynamo output is thereby limit¬ 
ed to a safe maximum. 






The Automobile Handbook 589 

Dyneto and Entz outfits do not make use of 
a cut-out of the usual form. The motor-dynamo 
is placed in circuit with the battery when the 
starting switch is closed and this switch is left 
closed as long as the machine operates. As 
soon as the unit has started the engine, the 



Pig. 287 

Pour Terminal Dyneto Motor-Dynamo 


engine causes the armature speed to increase 
to a point at which the voltage is greater than 
the battery and charging then commences. If, 
at any time, the armature speed falls below a 
certain point the machine again resumes its ac¬ 
tion as a starting motor. 



590 The Automobile Handbook 

The ignition is controlled by the same switch 
that makes the battery and motor-dynamo cir¬ 
cuit. With this switch in the “Off” position, 
the ignition is inoperative and the battery is 
disconnected from the motor-dynamo. With the 
switch in the “On” or “Running” position, 
the ignition is on and the battery is connected 
to the electric machine. A switch position mid¬ 
way between the two mentioned is provided, 
this position being called “Neutral.” With the 
switch at “Neutral,” the ignition is operative 
but the motor-dynamo circuit is open so that 
the battery will not discharge, and the machine 
will not act as a starting motor at low engine 
speeds. 

The number of terminals differs on various 
types; one with five connections being shown in 
Fig. 286 and another unit with four terminals 
being illustrated in Fig. 287. 


The Automobile Handbook 


591 


Gray & Davis Equipment. The type of equip¬ 
ment used from 1912 to 1914 is described below. 

This system comprises two units: t 1, the 
starting motor; 2, the dynamo for charging 



battery and lighting. The function of the dy¬ 
namo is to furnish current for lamps and cur¬ 
rent for the battery. The starting motor starts 
the engine. This motor is connected with the fly¬ 
wheel by gears, and when a starting pedal is 









592 


The Automobile Handbook 


pressed the motor turns the flywheel and crank¬ 
shaft and keeps turning until the engine “picks 
up.” The starting motor then automatically 
ceases to operate. 

The dynamo system includes the following: 

1, a constant-speed dynamo, driven from the 
engine or jackshaft by gear or a silent chain; 

2, a governor, to take care of the varying speed 
of the engine; 3, an electric cut-out, to discon¬ 
nect the dynamo from the battery when run¬ 
ning below the charging speed; 4, a battery to 
operate the lights when the dynamo is not run¬ 
ning at the necessary speed or when the en¬ 
gine is stopped. This battery may also be used 
for firing the engine. 

1. The dynamo is of the compound-wound 
type, designed to run at a constant speed of 
1000 revolutions per minute. The system is so 
wired that the series field is carrying current 
only when the lights are burning. See Fig. 289. 

2. The governor is of the simple, centrifugal 
type, but operates a friction clutch of new de¬ 
sign. In operation the clutch slips just enough 
to hold the dynamo speed always at 1000 
r. p. m., whether the engine speed corresponds 
to a car speed of 13 or of 60 miles an hour. 

3. The electric cut-out consists of an elec¬ 
tro-magnet with a compound winding, the fine 
wire part of which is connected across the dy¬ 
namo terminals. Its function is, as stated, to 
disconnect the dynamo from the battery when 
the engine is running very slowly or is at rest. 


The Automobile Handbook 


593 



cjbTju aruw 













































































594 The Automobile Handbook 

If an automatic switch of this nature were not 
in the circuit the battery would discharge 
through the dynamo when the dynamo was no 
longer maintaining charging voltage. 

4. A battery rated at 6 volts, 80-ampere 



hour capacity at a discharge rate of 8 amperes 
is furnished with this system sufficient to carry 
the full lamp load for ten hours or the side and 
tail lamps for thirty hours. The arrangement 



































The Automobile Handbook 


595 


of the switch connections is such that the 
dynamo operates as a shunt-wound' machine 
while charging the battery and as compound- 
wound when supplying the lamps directly. This 
gives the battery a tapering charge. 



The wiring for this system is plainly shown 
in the accompanying diagram. See Fig. 289. 

i 



































596 The Automobile Handbook 

The newer models of Gray & Davis equip¬ 
ment make use of a separate dynamo or ignition- 
dynamo with a combined output regulator and 
cut-out carried in a housing on top of the unit. 

The interior construction of the dynamo is 
shown in Fig. 291, the particular model illus¬ 
trated being arranged for carrying an ignition 
head at the drive end and providing a spiral 
gear drive. 

The cut-out and regulator are in the same 
case and the one large electromagnet operates 
both. This magnet carries two windings, shunt 
and series. When the dynamo is idle the cut¬ 
out contacts are open and the two regulator con¬ 
tacts are closed, being held that way by their 
respective springs. Fig. 292. Current enters 
the shunt coil of the controller through the 
grounded end and down through the terminal A 
to the negative brush, thus receiving current 
from between the brushes whenever the dynamo 
runs. When the voltage rises to a point in this 
coil so that the magnet overcomes the tension 
of the cut-out spring the cut-out contacts close. 
Current which has passed from the grounded 
positive brush of the dynamo through the bat¬ 
tery in charging, returns to the terminal B and 
passes through the entire length of the series 
coil on the magnet before going through the 
cut-out contacts to the terminal A and negative 
brush. Current which has passed through the 
lamps returns to the terminal L and through 
only a part of the series coil on the magnet 


The Automobile Handbook 


597 



Internal, Connections of Gray & Davis Vibrating 

Regulator System 




























































































598 The Automobile Handbook 

before reaching the negative side. The more 
lamps are turned on the more current they 
take and the less current is left to pass through 
the battery. It will therefore be seen that if 
enough lamps were turned on to- leave nothing 
going through the battery the part of the series 
coil between L and B would carry no current 
and the strength of the magnet would be weak¬ 
ened. For the same reason it will be seen that 
the more lamps turned on the weaker this coil 
and magnet become. This is part of the regu¬ 
lator action as will be explained. 

The regulator action is as follows: Current 
passes from the positive brush through the shunt 
field and into the terminals F and FI, then 
through the regulator contacts which are closed 
and back to the terminal A to the negative 
brush. As the voltage passing through the 
shunt magnet coil increases- after the cut-out 
has closed, its strength finally reaches a point 
where the tension of the regulator contact spring 
is overcome and the contacts are pulled open. 
The current from terminals F and FI must 
now return to the negative brush through the 
resistance wire coils seen between the two regu¬ 
lator contacts, this resistance retarding the flow 
and weakening the dynamo fields and conse¬ 
quently lowering the output and voltage until 
the weakened magnet allows the regulator con¬ 
tacts to again close. This action causes these 
contacts to vibrate and keep a steady output. 
As explained above, the strength of the magnet 


The Automobile Handbook 599 

is decreased as more lamps are turned on, so 
that the regulator contacts remain closed for a 
longer time, and, as the resistance is not in the 
field when they are closed, the output is allowed 
to rise to care for the added lamp load. 

The cut-out is of the simple electromagnetic 
type. The action of the regulator allows the bat¬ 
tery to receive a small charge even with all 
lamps on. 

Removable plates cover either side of the dy¬ 
namo, allowing access to the inside without dis¬ 
turbing any parts or wires. 

A charge indicator is located on the dash or 
cowl. The pointer turns upward if current is 
passing to the battery and downward when cur¬ 
rent passes out of the battery for any purpose. 
If the pointer is straight across the battery is 
neither charging or discharging. This indi¬ 
cator should show charge at car speeds above 
10 to 12 miles per hour. 

The output of the dynamo may be tested by 
turning on all lamps and disconnecting the wire 
from terminal B. The lamps are then burning 
directly from the dynamo and if they go out the 
dynamo is at fault. 

The regulator and cut-out may be tested by 
connecting a wire from terminal A to terminal 
B while the engine runs at a speed which would 
correspond to a car speed greater than 10 miles 
per hour. If the indicator then shows charge 
when it failed to show this before the test the 
cut-out or regulator is at fault. If the indi- 


600 


The Automobile Handbook 


cator remains straight across something is pre¬ 
venting the dynamo from delivering its cur¬ 
rent. 

The lighting switch is of the rotary snap type 
and carries all lamp and circuit wires op the 
engine side. On the back of the switch are four 
fuses in clips. Near the fuses are letters H, S, 
R and B, indicating the fuses for head, side or 
dimmer, rear and tail, ignition and horn cir¬ 
cuits respectively. 



Fig. 293 

North East Motor-Dynamo 


The starting motor drives into a flywheel ring 
gear or crankshaft through sliding reduction 
gearing and overrunning clutch. The starting 
switch pull rod operates the sliding gear through 






The Automobile Handbook 


601 


a coil spring so that switch contacts may close 
whether gears are in position to mesh or not, 
the first turning of the armature causing the 
gears to snap into mesh under the action of the 
compressed spring. One side of the starting 
switch may be grounded or the lead from the 
positive motor brush may be grounded. In 
either case two wires lead to switch and start¬ 
ing motor. 

North East Equipment. This starting and 
lighting system makes use of a combined motor- 
dynamo having two field windings, a shunt and 
series. The series field is used for starting and 
the two fields compound for generating. One 
of these units is shown in Fig. 293. 

The brushes and commutator may be exposed 
by removing a cover from the end opposite the 
drive. The upper part of this cover, which en¬ 
closes the brushes, is held in place by spring 
clips, but the lower half is fastened with bolts 
that are sealed at the factory. This lower half 
encloses a combined cut-out and regulator. The 
cut-out is of the electromagnetic type and serves 
to connect the dynamo with the battery when 
the generating voltage is sufficiently high to 
make charging possible, also to disconnect the 
battery when the dynamo voltage falls below 
that of the battery. 

The regulator is of the vibrating reed type, 
having two sets of contacts operated from one 
electromagnet. The current output of the dy¬ 
namo passes through the winding of the regu- 


602 The Automobile Handbook 

lator electromagnet and causes the contact to 
open when the amperage has reached a certain 
predetermined limit. With the contacts open, 
the field current, which has previously passed 
through the contacts, must flow through two 
spools of resistance wire. The consequent re¬ 
duction in field current prevents further rise in 
output. 

North East equipment is of the two volt¬ 
age type, the starting voltage being either 12, 
16 or 24, while lighting and charging is ac¬ 
complished at 6. 8 or 12 volts. Starting and 
charging circuits are of the two wire type, 
while lighting circuits may be either one wire 
with ground return or two wire throughout. 
A field fuse is carried in the brush and com¬ 
mutator compartment of the motor-dynamo, 
this fuse blowing out should the battery or 
charging lines become disconnected while the 
motor-dynamo is operating. 

The unit is driven from the engine and 
drives to the engine through a silent chain, 
with or without spur gear reduction. 

Remy Equipment. Remy apparatus con¬ 
sists of a variety of types, each one suited to 
the particular requirements of the cars to 
which it is applied. A complete internal cir¬ 
cuit diagram of one of the separate unit sys¬ 
tems with separately mounted regulator and 
cut-out is shown in Pig. 295. 

Remy equipment may be made up of all 
separate units for lighting, starting and igni- 


The Automobile Handbook 603 

tion, with or without Remy magneto or battery 
ignition. The separate unit systems all make 
use of a shunt wound dynamo of 6 volt out¬ 
put. The separate motors are of four pole, 
series wound type and operate on 6 volts. 

A separate dynamo may be driven from a 
shaft to the timing gear ease and have one of 
the separate motors mounted above it, forming 
a “double deck” instrument. The dynamo 
would be two pole shunt wound and the motor 
four pole series wound, both 6 volts. The 
motor drives down to the main shaft through 
two pair of spur reduction gears, the large gear 
on the main drive shaft carrying an overrun¬ 
ning clutch which runs free while the starting 
motor operates. 

Another Remy system makes use of a motor 
dynamo with only one armature. This machine 
is of the four pole type, compound wound and 
operates with 12 volts. No overrunning clutch 
or device taking its place is used with the sin¬ 
gle armature motor dynamos, these being di¬ 
rect connected in all cases. 

Remy dynamos are also built with a mag¬ 
neto type breaker mounted on one end of the 
armature shaft with a magneto distributer car¬ 
ried above it, thus forming a combined dyna¬ 
mo-ignition outfit. The dynamos in this case 
are of the two pole shunt wound type operating 
with 6 volts. These machines are positively 
driven at engine speed in four cylinder cars 
one and one-half times engine speed in six cylin- 


604 


The Automobile Handbook 

der cars and twice engine speed in eights. A 
separate 6 volt starting motor is used in con¬ 
nection. 

The 12 volt motor-generators (as described) 
are also built with the ignition breaker and dis¬ 
tributer added, forming a single unit having 
the functions of starting motor, dynamo and 
igniter in one. 

Wiring for lighting, charging and starting 
circuits may be either two wire or one wire 
with grounded return. Switches, current in¬ 
dicators, junction boxes and dimmer resistance 
units vary with the make of car. 

Regulation of the amperage is accomplished 
in either of two ways. One method is by the 
third brush being below one of the main brushes 
on the left side facing the commutator. This 
brush takes current to one end of the shunt 
field winding, the amount of current flowing 
through this brush becoming less and less as 
the speed increases. The position of the brush 
is not adjustable. 

The other method of regulation consists of an 
electromagnet carried in the same case with 
the, cut-out and operating to insert a coil of 
resistance wire, also carried in this case, into 
the shunt field circuit as the amperage rises. 

The cut-out is of the electromagnetic type 
with two windings, shunt and series. The cir¬ 
cuit should close in the neighborhood of ten 
miles per hour, preferably at lower speeds. The 
cut-out mechanism or combination of cut-out 


The Automobile Handbook 


605 





irv* 


COM Bin CD LIGHT INC IGNITION COIL 

IGNITION MITCH BCM5THNCC O- 























































































606 


TJte Automobile Handbook 


and regulator may be mounted on the dynamo 
housing at the drive end over the armature 
shaft or as a separate unit on the dash or other 
convenient location. 

The current output should be about 7 am¬ 
peres at 8I/2 to 12 miles per hour, rising to a 
maximum of 10 to 14 amperes, depending on 
the installation. 

Starting motor drive may be through reduc¬ 
tion gearing inside the housing as described 
for the double deck instruments; or by chain 
with overrunning clutch on separate motors 
but without the clutch on motor-dynamos. Sep¬ 
arate motors also use the Bendix type of in¬ 
ertia pinion drive. 

Starting switches are of two types, both mak¬ 
ing the circuit complete without preliminary 
contacts. One uses the conventional type of 
tapered plunger, the other uses copper bands 
sliding on two cylinders, the cylinders being 
made of insulating material and carrying con¬ 
tact bands in such a position that the sliding 
rings complete the circuit from one cylinder 
to the other when fully depressed into position. 
Either switch may act by push or pull rods or 
foot buttons. 

Puses for each of the lighting lines are car¬ 
ried in the lighting switch. A 20 or 25 ampere 
fuse in circuit with the dynamo field is mounted 
above the magnet in separate cut-outs or on the 
base of combined regulators and cut-outs. 


The Automobile Handbook 


607 


A number of models of Remy generators are 
built with a third brush type of regulation and 
have, in addition, a thermostatic control which 
is peculiar to these systems. The principle of 
this control is shown in Figure 295, the drawing 
at the upper left showing the thermostat with 
the contacts closed, the drawing at the lower 
left showing the contacts opened with the ther¬ 
mostat heated, while at the right is shown the 



connection of the device in the field circuit of 
the generator. 

The thermostat is composed of a resistance 
unit, shown connected between the upper and 
lower parts, two silver contact points and a 
spring blade which carries one of the contact 
points. This blade is made of a strip of spring 
brass welded to a strip of nickel steel, a com¬ 
bination which will warp when heated, due to 
the greater expansion rate of the brass. At low 






















608 


The Automobile Handbook 


temperatures the contacts are held together, but 
at approximately 175° Fahrenheit, the blade 
bends and separates the points. 

When the thermostat contacts are closed, with 
the parts cold, the full field current from the 
third brush passes through them and permits 
full output from the generator. After ttie en¬ 
gine runs long enough for the parts to become 
heated, the opening of the contacts causes the 
field current to pass through the resistance with 
the result that the reduced flow cuts the charg¬ 
ing rate to a lower amperage. 


The Automobile Handbook 609 

Rushmore Equipment. The Rushmore system 
was originally manufactured by the Rushmore 
Dynamo Works, but this company is now a part 
of the Bosch Magneto Company, and the prod¬ 
uct is known as “Bosch-Ruslimore” and 
“Bosch.’* The several unique features found 
in this equipment are described on the follow¬ 
ing pages: 

The Rushmore Engine Starter. The Rush¬ 
more electric starting motor, shown in Pig. 
296, acts directly on the flywheel without in¬ 
termediate gears, a pinion keyed fast on the 
motor shaft meshing with a gear on the fly¬ 
wheel rim. This pinion is normally out of en¬ 
gagement. The closing of the starting switch 
causes the pinion automatically to engage the 
flywheel gear before the armature starts rotat¬ 
ing. As soon as the engine picks up, the pinion 
automatically slides out of mesh, and remains 
out no matter how long the starting switch is 
held closed. There is no mechanism except the 
starting motor itself and the starting switch. 

When the starter is not in use the armature 
is held normally out of line endwise with the 
pole pieces by means of a compression spring 
contained in and acting against the hollow 
armature shaft. Magnetic pull is employed to 
engage the pinion. The foot button starting 
switch has three contacts. At the first pres¬ 
sure upon the button the armature is drawn 
into the field with great force while rotating 
slowly so that the pinion teeth will engage. 
After the gears are fully engaged the third 


610 The Automobile Handbook 

contact applies the full force of the battery to 
turn over the engine. 

The motor is series wound and produces a 
strong torque on starting. As soon as the en¬ 



gine picks up, the accelerated speed causes the 
counter electro-motive force in the motor to 
reduce the current flow to a value too small to 
hold the armature in line with the pole pieces 
against the end pressure of the spring. The 







The Automobile Handbook 


611 


pinion then slips out of mesh and remains out, 
even with the circuit closed, because the cur¬ 
rent required to run the motor free is too small 
to overcome the spring. The armature will 
not again move endwise into its working posi¬ 
tion until it has stopped and the switch is 
again closed. The turning force developed at 
the flywheel rim is rated at over 400 lbs., suffi- 


4RON 

BALLAST 

COIL 



Fig. 297 —Diagram of Rushmore Lighting System. 


cient to start the largest engine with ease. The 
motor is wound for a 6-volt battery. 

Rushmore Lighting System. Essential ele¬ 
ments of this system are: 1, the dynamo; 
2, storage battery, 6-volt, of 80 to 160 ampere 
hours capacity, depending upon size of the 
headlights; 3, switch and terminal block on 
























612 The Automobile Handbook 

dashboard, which simultaneously switches the 
headlights on or off and switches the ballast 
coil in or out of circuit; 4, wiring and circuit 
switches for small lamps. 

■ Briefly the action of the dynamo is to reduce 
the strength of the field magnet at high speeds 
by means of counter excitation produced by a 
few turns of magnet wire, called a “bucking 
coil,” on the field poles. The amount of cur¬ 
rent passing through this bucking coil is deter¬ 
mined automatically by the varying resistance 
of a small coil of iron wire, called the “ballast 
€ 00 /' which is made in the form of a cartridge 
fuse and carried in clips on the switchblock in 
the main line between the dynamo and the bat¬ 
tery. See Fig. 297. The effect of controlling 
the bucking coil by the current output is to pro¬ 
duce an approximately constant current at the 
higher speeds. 

Simms-Huff Equipment. This apparatus 
as generally mounted consists of a combined 
dynamo, and motor with separate magneto ig¬ 
nition. One wire system with a grounded re¬ 
turn for all circuits is used. 

The motor dynamo is of the six pole type 
and has a differential compound winding. It 
generates 6 volts as a dynamo and operates with 
12 volts as a motor. The drive for dynamo 
purposes is by belt from the fan pulley and 
crankshaft. When operated as a motor the 
engagement is through a pinion which slides 
on a counter shaft between the armature shaft 


The Automobile Handbook 613 

and flywheel ring gear and completes the me¬ 
chanical connection. 

The starting switch which makes the necessary 
changes in connections for charging or start¬ 
ing is located on the transmission case and the 
operating parts also act to slide the gears into 
mesh through the action of a stiff coil spring. 
Should the gears not match exactly, the spring 
compresses and allows the switch to close when 
the first movement of the armature under the 



Fig. 298 

Simms-Huff Motor Dynamo 


starting current brings the gears into position 
and the compressed spring forces them into full 
engagement. 

Regulation of output is maintained at a suf¬ 
ficiently high value (15 amperes maximum) by 
adjusting the tension of the driving belt. Ex¬ 
cess-output is prevented by the differential ac- 






614 


The Automobile Handbook 


tion of the reversed series field winding and 
by a separate regulator having an electromag¬ 
net which acts to insert resistance in the shunt 
field winding with rise of amperage. This 
electromagnet regulator is carried in a housing 
with the cut-out. The output is adjustable by 
changing the tension of the flat spring. 

The cut-out is of the electromagnetic type 
having two windings and the time of opening 
and closing is adjustable by a small screw. 

Two 6 volt, 35 ampere hour batteries are 
carried in one box under the front seat, being 
connected in series for starting and parallel 
for lighting and charging. A combined light¬ 
ing and ignition switch is carried; inserting 
the plug turns ignition on. 

Headlight dimming resistance is carried on 
the engine side of the switch and an ammeter 
switch and an ammeter is mounted on the dash. 

Splitdorf-Apelco Equipment. The electri¬ 
cal unit for these equipments is shown in Fig. 
299, and its connections with the balance of 
the apparatus is shown in the wiring diagram, 
Fig. 300. The wiring shown applies to the 
equipment operating at 12 volts for starting 
and 6 volts for charging and lighting. 

These systems use a combined motor dynamo 
which may also carry an ignition breaker and 
distributor on a separate vertical head driven 
from one end of the motor dynamo unit. The 
system is therefore of one or two unit type, 
no separate starting motors being used. A 


?he Automobile Handbook 615 

dynamo which does not act as a starting motor 
is used on the Stanley steam car. All gas cars 
use motor dynamos. 

The unit has four poles, three windings on the 
fields. One coil is ordinary shunt and acts as 



Fig. 299 

Splitdorf-Apelco Motor-Dynamo 


a shunt in both generating and starting. The 
output is controlled by a separate bucking 
coil through which all current from the dynamo 
passes, this opposing the shunt more and more 
as the speed, voltage and amperage increase. 
The third coil is a series winding for starting 



616 The Automobile Handbook 

motor action, though it also assists the shunt 
while generating, making a compound dynamo 
with bucking coil and a compound motor. 



Two voltage combinations are used. One 
charges the battery and starts on 12 volts, us¬ 
ing a six cell battery with all cells in series for 


Fig. 300 

Splitdorf-Apelco Wiring for 12-6 Volt System 

































The Automobile Handbook 617 

charging, starting and lighting. This is called 
the straight twelve system. 

The other system uses a six cell battery di¬ 
vided in two sections of three cells each and is 
charged with the two parts in parallel at 6 
volts. This system uses all cells in series with 
12 volts for starting while lighting is from the 
parallel connections, thus giving 6 volt charging 
and lighting and 12 volt starting, the proper 
connections and changes being made in the 
starting switch. This is the twelve-six volt 
system. 

Both types use separate electromagnetic cut¬ 
outs mounted on the dash in all cases. The 
cut-out carries two windings. The movable arm 
carries a marker which shows the word OFF 
on a dial whenever the contacts are open and 
the word ON whenever the contacts are closed. 
ON simply indicates that the current is flow¬ 
ing from the dynamo, but according to the 
number of lamps turned on it may be going 
to the battery or to the lamps or may be divid¬ 
ing between them. The engine speed at which 
the cut-out opens and closes may be changed by 
a small screw passing through the cut-out 
spring. This screw may be turned to either 
lessen or increase the spring tension, thus low¬ 
ering the cut-in speed or raising it accordingly. 

The dynamo without starter action is a four 
pole shunt wound machine operating at 6 volts. 
Regulation is with a third brush which carries 
all the current flowing to the shunt field. 


618 


The Automobile Handbook; 


U. S. L. Equipment. Two distinctly different 
types of equipment have been marketed by the 
United States Light and Heating Company. The 
first type, which is described first, was used up 
to and including part of the year 1915. This 
type comprises a motor-dynamo mounted on the 
engine crankshaft with the controlling ele¬ 
ments, cut out and regulator, carried in a hous¬ 
ing on the driver’s side of the dash board. 

The type referred to above is known as the 
“external regulator” type, while the newer 
system is the ‘ ‘ inherently regulated ’ ’ type. This 
newer system makes use of a cut out on the 
dash, but secures regulation of current output 
by allowing the dynamo current, when exces¬ 
sive, to react on part of the field, and by reduc¬ 
ing the field magnetism in proportion to the 
speed and output, a proper rate of dynamo 
charge is maintained. 

U. S. L. Electric Motor Generator. In the 
system employed by the United States Light 
& Heating Co., with which many automobiles 
are now equipped, an electric motor generator 
is an integral part of the gasoline motor and 
furnishes current for starting and lighting. 
The system includes, besides the motor gen¬ 
erator, an automatic current regulator, an oil 
switch and a storage battery. 

The motor generator comprises a set of field 
coils, armature and commutator and brush 
ring. These parts replace the flywheel of the 
gasoline motor, being attached to the crank- 


The Automobile Handbook 


619 


shaft in its stead. They are inclosed in an 
aluminum case and dust ring. 

When a starting button is pressed down, the 
current from the storage battery starts the 



Q* 

S 


4 

m 

4 

! 

o 

CO 


tb 


motor generator. This revolves the crankshaft 
of the gasoline motor. With the switch of the 
’.gnition coil in either magneto or battery posi¬ 
tion, the gasoline explosions commence. The 
foot starting button is then released, when the 






620 The Automobile Handbook 



Fig ; 302—Wiring Diagram of U. S. L. Starting System. 



































































The Automobile Handbook 621 

electric motor automatically changes into an 
electric generator. As the speed of the gaso¬ 
line motor increases, the generator gradually 
begins charging the battery, restoring the cur¬ 
rent discharged during the starting operation. 

An automatic regulator, controlling the cur¬ 
rent to the battery, is located in the center of 
the dash. It has a charging indicator, the func¬ 
tion of which is to show that the circuit is 
closed at the proper time, or at a speed of 12 to 
14 miles an hour, and that the circuit is open 
when the car speed drops below about 10 miles 
an hour or the motor stops altogether. The 
regulator consists of a compound-wound mag¬ 
net and a variable resistance with magnet bar 
and contacts for controlling field current in 
the generator. 

The oil switch is included in this system to 
change the electric motor into an electric gen¬ 
erator upon the release of the starting button. 

The type of U. S. L. equipment in most gen¬ 
eral use at present does not use the externally 
mounted combined cut-out and regulator but 
secures regulation of the output as a dynamo 
by means of a third brush system in which the 
flow of current through one of the field cir¬ 
cuits depends on the current flowing into one 
of the brushes. The system is known as “ In¬ 
herently Regulated.’ ’ An electromagnetic cut¬ 
out is mounted on the dash of the car and 
serves the purpose of connecting the * dynamo 
and battery when the dynamo voltage is suffi- 


622 The Automobile Handbook 

cient for charging. The complete internal con¬ 
nections for this type of application are shown 
in Fig. 303. 

Above the cut-out are carried two fuses, one 
of six empere capacity and one of 30 ampere. 
The six ampere fuse is in the field circuit and 
will blow out should the battery lines become 
disconnected with the dynamo operating. The 
thirty ampere fuse is in the main charging cir¬ 
cuit. 

The touring switch used with U. S. L. equip¬ 
ment may be opened when the car is used on 
long daylight runs, and by thus opening the 
field and charging circuit of the motor-dynamo, 
excessive battery charge is prevented. The 
two lamp combinations in use with this type 
are shown in Fig. 303; one of these being a 
three wire system with 7 volt lamps, and the 
other being the usual two wire system with 
14 volt lamps. In either case, starting is ac¬ 
complished with 24 volts and charging at 12 
volts, the proper changes: in connections be¬ 
ing made in the starting switch. # . 

The relative location of the parts of a U. 
S. L. system having inherent regulation and 12 
volt pressure for all functions is shown in 
Fig. 304. 

Wagner Equipment. Wagner apparatus 
may consist of a combined motor-dynamo with 
cut-out and starting switch mounted on the 
unit, or of separate motors and dynamos with 
a cut-out on the dynamo or mounted separately. 


The Automobile Handbook 


623 



Fig. 303 

Internal Connections of U. S. L. 24-12 Volt In¬ 
herently Regulated Motor-Dynamo System. 








































624 


The Automobile Handbook 


The motor-dynamo is a compound wound ma¬ 
chine using the series fields for starting. The 
output is controlled by taking the shunt field 
current through a “third brush” which is so 
placed that excessive amperage is prevented at 
high engine speeds. 

On top of the unit is a housing in which is 
an electromagnetic cut-out and also a rotary 
drum starting and charging switch. This 
switch makes such connections that starting is 
accomplished with 12 volts pressure by ar¬ 
ranging all battery cells in series, while charg¬ 
ing and lighting are at 6 volts with the two 
battery sections in parallel. 

The motor-dynamo is driven from the engine 
by means of a chain to the front end of the 
crankshaft and is driven from the engine by 
this same chain. The necessary gear reduction 
for starting is secured through a planetary form 
of gearing carried in a housing ahead of the 
unit, this gearing being brought into play by 
a brake band that is tightened by the same 
operation with which the driver moves the 
rotary switch to the starting position. 

If the dynamo, motor and ignition are all 
separate, the dynamo is shunt wound. Four 
brushes bear on the commutator, two receiving 
the main charging current. The other two 
brushes are slightly nearer together. The sec¬ 
ond pair of brushes carries the current to the 
shunt field and because of their location with 
reference to each other act to decrease the cur- 


The Automobile Handbook 


625 


rent flowing to the field at high speeds because 
of the distortion of the path of the magnetism 



Fig. 304 

Arrangement of Parts in U. S. L. Motor-Dynamo 
System 

between the field poles. This regulation action 
prevents excessive charging rates at high speeds 





























626 


The Automobile Handbook 



and causes the output to be slightly decreased 
at these speeds. The action of this form of 
regulation is also to increase the output with 
the increase in battery voltage so that the flow 
is greater to a battery when nearly charged 
than when nearly empty. 


Fig. 305 

Wagner Starting Motor With Gear Reduction 
L and M, Brush Holders 

The starting motor, Fig. 305, drives through 
a spur gear reduction and chain to the front 
end of the crankshaft. An overrunning clutch 
is built into the sprocket on the crankshaft. 
The starting switch makes the circuit complete 
without any preliminary resistance, the clutch 
providing the engagement. 







The Automobile Handbook 627 

Westinghouse Equipment. Three distinct 
types of Westinghouse apparatus are in use. 
The first, and oldest, type makes use of a sep¬ 
arate dynamo securing output, regulation by 
means of a bucking coil fifeld as described in 
the following pages, and having an electromag¬ 
netic cut-out mounted on the dynamo. Another 
type includes a separately mounted dynamo 
having a vibrating reed voltage regulator and 
an electromagnetic cut-out mounted on the 
dash board or inside of the dynamo housing. 
The third type consists of a combined motor* 
dynamo having third brush regulation^ 

In generating current the machine acts as 
a shunt wound dynamo, the reversed series 
coil acting to regulate the amperage in a way 
peculiar to these systems. One end of the re¬ 
versed series coil is connected to one of the 
dynamo brushes in such a way that current 
flowing into the battery for charging passes 
through this coil and by opposing the shunt 
winding keeps the amperage down to a proper 
point. The line which leads to the lamps from 
both battery and dynamo is attached to a lead 
from the differential winding in 'such a way 
that current from the dynamo to the lamps 
does not pass through the bucking coil. That 
means that the amount of current which flows 
through the bucking coil with the lamps off 
is the entire amount from the dynamo going to 
the battery, but as soon as the lamps are turned 
on a part of this current passes to the lighting 


628 The Automobile Handbook 

lines and no longer goes through the bucking 
coil. The reduced flow through the bucking 
coil with lamps on allows the shunt field to 
exert its effect without so much opposition and 
the output accordingly rises to care for the 
additional lamp load. Should enough lamps be 
turned on to take the entire dynamo current, 
none will be left to the bucking coil and the 
dynamo will act as a shunt machine without 
opposition and give the fullest current flow 
of which it is capable under these conditions. 
Should still more lamps be turned on the ad¬ 
ditional • current will flow to the lamp lines 
from the battery through the differential wind- 



Open c/osed 


Fig. 306 

Westinghouse Cut-out Used With Inherently Reg¬ 
ulated Dynamos 

ing, but in an opposite direction from which it 
passed in bucking the shunt action and will 
therefore serve as an additional series winding 
assisting the shunt and the machine is there¬ 
fore compound under these conditions and the 
output is still further increased. 

All dynamos of this type carry an electro¬ 
magnetic cut-out, Fig. 306, on the dynamo hous¬ 
ing at the drive end just above the saaft, the 










The Automobile Handbook 


629 


magnet carrying two windings as is the usual 
practice. This cut-out should close at about 
8 miles per hour and re-open at about 6 miles 
per hour. It has no means of regulating the 
time of opening and closing. The wiring for 
this system is shown in Fig. 307. 

The dynamo having voltage regulation is 
of the shunt wound type and the regulator acts 
to insert a resistance in the field when the 
terminal voltage rises to the predetermined 
limit. The operating parts of the combined cut¬ 
out and regulator are shown with the cut-out 
open in Fig. 308, and with the cut-out closed 
in Fig. 309. The complete internal connections 
of the voltage control dynamo with self con¬ 
tained regulator and cut-out are shown in Fig. 
310. 

When the dynamo is being operated at a 
speed below the predetermined “cut-in speed”, 
the contacts of the cut-out armature are open, 
the voltage of the dynamo being below that of 
the battery. When the speed reaches the * 4 cut- 
in speed” these contacts are closed, connecting 
the dynamo circuit to the battery circuit. The 
“cut-in speed” varies from five to ten miles 
per hour on high gear, depending upon the 
gear ratio and wheel diameter of the particular 
car. 

The “cut-in speed” can be observed by run¬ 
ning the car, allowing it to increase in speed 


630 The Automobile Handbook 

slowly, and observing on the speedometer the 
speed at which the car is running when the 
cut-out contacts close, which is indicated by a 
slight movement of the meter needle. 



Fig. 307 

Wiring of Westinghouse Ignition and Lighting 
System, Inherently Regulated 


C (IPI ® w, ’U. o 


© ^ ^ ^ o 




\ 


. 


Open ' Closed 

Fig. 308 Fige. 309 

Westinghouse Voltage Westinghouse Voltage 
Controller, Cut-out Open Controller, Cut-out Qosed 


The regulator is so constructed that the cut¬ 
out operates to disconnect the dynamo from the 
battery circuit at a speed slightly below the 
‘ 1 cut-in speed”. This enables the cut-out to 







































The Automobile Handbook 


631 


keep the circuit closed, and not constantly open 
•r close it when the car is being run at speeds 



Internal Connections of Westinghouse Self-Con* 
tained Voltage Control Dynamo 

close to “cut-in speed”. This disconnecting 
of the dynamo from the battery circuit when 







































632 The Automobile Handbook 

the dynamo voltage is below the battery volt¬ 
age insures that the battery will not be' dis¬ 
charged through the generator. 

The shunt fields of the dynamo are so de¬ 
signed that a voltage in excess of the normal 
voltage would be regularly generated when the 
dynamo is operated at high speed and no load. 
This excess voltage is prevented and the volt¬ 
age is held constant by the automatic voltage 
regulator. When the dynamo is operating be¬ 
low “cut-in speed’’ the contacts of this regu¬ 
lator are closed, and remain closed until the 
armature is revolved at a speed which gener¬ 
ates a voltage in excess of a predetermined 
value. This voltage is fixed by the setting of 
the voltage regulating screw which is adjusted 
at the factory. When, due to the increased 
speed of the dynamo, the voltage tends to ex¬ 
ceed the value for which the regulator is set, 
the regulating contacts open, opening the di¬ 
rect shunt-field circuit and cutting in the regu¬ 
lating resistance. This causes a momentary 
drop in voltage so that the contacts close again. 
This opening and closing of the contacts is 
continuous, and so rapid as to be impercepti¬ 
ble to the eye. 

Dynamos are also furnished with ignition 
parts carried on one end of the dynamo frame, 
these parts consisting of a magneto type 
breaker which automatically advances the spark 
by a pair of governor weights acting as the 
breaker cams and a distributor mounted above 


The Automobile Handbook 


633 


the breaker. Otherwise the unit is the same as 
the dynamos described. 

The combined motor dynamos are four pole 
compound wound machines operating with 12 
volts, while the electromagnetic cut-out may or 
may not be employed. When the cut-out is 
used it is carried as a separate unit. These 
machines drive to the crankshaft direct through 
chains or gears without the use of overrun¬ 
ning clutches. 

Almost all Westinghouse installations use the 
single wire system with the positive side of 
the circuit grounded in all cases. The ground 
return for the starting motor is assisted by hav¬ 
ing the cable enclosed in copper tubing which 
is attached to the metal work of the car and 
which is therefore free to carry the current to 
the motor. 

The lighting switch is usually of the push 
button type. All circuits are fused, the cart¬ 
ridge fuses being carried in fuse boxes which 
provide for 3, 4 or 5 circuits in addition to the 
line to the battery. The fuse for head and 
tail lamps should be 15 ampere, for side and 
tail 5 ampere, for tail alone 3 ampere and for 
additional circuits such as the horn 15 ampere. 
When 6 volt bulbs are used with short wiring 
one of the fuses is replaced with a coil of re¬ 
sistance wire so that the voltage to the lamps 
with short connections may not be excessive. 
With 7 volt bulbs this compensator coil is un¬ 
necessary. Head lamps may be dimmed by 


634 The Automobile Handbook 

throwing them in series or by arranging a re- 
stance coil in one lead to the lamps. Junc¬ 
tion boxes are used to centralize the connec¬ 
tions and disconnector blocks are used for al¬ 
lowing body removal. Either an ammeter or 
voltmeter may be used, the ammeter being con¬ 
nected on one of the battery lines to the lamps 
and dynamo in the usual way while the volt¬ 
meter is directly connected to the two sides of 
the battery, indicating the voltage at all times. 
The current drawn by the voltmeter is so small 
that it can be neglected in every way. 

Separate starting motors are of the four polo 
type, series wound with the field coils carried 
on two of the four poles, and operate with 6 
volts. 

Starting motors may drive the engine in any 
of five different ways. One system drives from 
a pinion on the armature shaft to a larger spur 
gear on a counter shaft, this larger gear hav¬ 
ing an overrunning clutch built into it. 
Mounted on the counter shaft is a small pin¬ 
ion which is free to slide on the counter shaft 
until it meshes with teeth on the fiywheel rim. 
This sliding pinion is moved by a yoke and rods 
from the foot pedal, these operating rods also 
operating the switch. The first movement of 
the pedal closes the circuit through preliminary 
contacts and resistance ribbon, causing the 
starting motor to whirl with little power. 
Further movement of the pedal breaks this 
electrical connection but leaves the motor spin- 


The Automobile Handbook 


635 


ning while the movement pulls the gears in 
mesh. After the gears are meshed the switch 
has traveled to a position in which full con> 
tact is made and the motor turns the engine. 
Releasing the pedal opens the switch and the 
gears are thrown out of mesh by a coil spring 
in the gear housing. 



Internal Connections of Westinghouse Magnetic 
PiDion Shift Starting Motor Drive 


Another system uses the same arrangement 
of gearing between armature shaft and fly¬ 
wheel teeth but the gear meshing and closing 
of the switch is accomplished by solenoid ac¬ 
tion, in place of by foot power. Three switches 
are used, Fig. 311, one being a push button on 
the dash marked * 1 start,” another being a 
small cylindrical housing through which the 
large starting cable runs and to which the wire 
from the dash button also leads and the third 
being the starting switch which is connected ta 
the shifting pinion as previously described. 






















636 


The Automobile Handbook 


Pressing the dash button allows current to 
flow from the battery to the small cylinder¬ 
shaped switch and through the windings of a 
magnet on this switch. This magnet pulls the 
contacts closed which allow the battery current 
to pass through and to the large starting switch. 
The large switch contains a powerful solenoid 
coil through which the current then flows and 
out through a small auxiliary wire to the 
ground. The solenoid immediately pulls on 
a plunger which is attached to the sliding gear 
and starting switch contacts and the action of 
closing the contacts and sliding the pinion into 
mesh is done by the pull of the solenoid in the 
same way as previously described for the foot 
button action. As soon as the engine starts 
it runs the dynamo and the voltage of the 
dynamo rises to a point equal to the battery 
voltage. This balance of pressure prevents any 
more current from flowing through the switch 
operated from the dash button and the main 
starting cable contacts open whether the dash 
button is released or not. This kills the sole¬ 
noid action and all parts return to normal 
positions. 

The starting motor may also drive to the 
crankshaft through gearing or chains with 
overrunning clutch in which case the starting 
switch makes full contact in the first position. 

Some installations drive to the flywheel by 
means of a Bendix type of application. 


The Automobile Handbook 


637 


Steel. Steel is composed of extremely minute 
particles of iron and carbon which form a net¬ 
work of layers and bands. The carbon content 
of the steel is generally specified according to 
4 ‘points,’’ a point being one one-hundredth part 
of one percent of the weight of the metal. A 
40 point steel therefore contains 40/100 or 2/5 
of one percent carbon. The greater the amount 
of carbon the harder and more brittle will the 
metal become. 

Other elements commonly found in steel in¬ 
clude the following: Silicon, which increases 
the hardness, brittleness, strength and difficulty 
of working. Phosphorus, which hardens and 
weakens the metal, but which makes it easier 
to cast. Sulphur, which tends to make the metal 
hard and porous. Manganese, which makes the 
steel hard and tough and of great tensile / 
strength. Aluminum, which in small quantities 
helps to prevent blowholes. Chromium, which 
increases the strength; this element being often 
combined with nickel as an alloy. Tungsten in¬ 
creases the hardness without making the metal 
brittle. Vanadium increases the elastic limit, 
making the steel stronger and tougher. 

Steel is made from cast iron either by the 
crucible, the Bessemer or the open hearth 
process. Steel may have a tensile strength vary¬ 
ing from 50,000 to 300,000 pounds per square 
inch, depending on the carbon, other alloys and 
heat treatment. 


638 The Automobile Handbook 

Steering Gear—Principles of. In steering 
gears the generally accepted principle is that 
known as the Ackermann-Jeantand, which was 
invented in 1878 and is a modification of the 



Designing Steering Knuckle Arms 
original Ackermann principle. In the Acker- 
mann-Jeantaud system the steering knuckle 
arms OL and O x L, when produced, meet in the 
plane of the rear axle or in this plane produced 
as shown by illustration, Fig. 313. The reader 
will appreciate that when the tie-rod L L is in 












The Automobile Handbook 


639 


rear of the front axle, the steering knuckle 
arms, OL and 0 J L converge, as illustrated, but 
should the tie-rod be in front of the axle, these 
arms diverge. Strictly speaking, the points A 
and AI, which are supposed to be in the axle 



plane, are not so, and the axle line A, AI, is a 
tangent to the curve in which the points of con¬ 
vergence will fall in a complete sweep of the 
steering wheels from axle to axle. 





















640 


The Automobile Handbook 


It will be realized from the foregoing ex¬ 
planation that the dimensions and proportions 
of the steering axle parts depend on the wheel¬ 
base of the car, inasmuch as with a longer 
wheel base the distance that the lines would be 
produced would be greater with the increase. 



Fig. 314 







The Automobile Handbook 


641 


Several makers have, however, discontinued 
the design of steering knuckles on this princi¬ 
ple, preferring to design them as illustrated in 
Fig. 312, in which the produced axis of the 
front w r heels, A and B, intersect the axis of the 
rear wheel at a given point O. With this con¬ 
dition fulfilled, the vehicle w T ill travel around O 
as an imaginary center. Enthusiasts of this 
method of construction agree that the Acker- 
mann-Jeantaud principle is sufficiently accu¬ 
rate for angles of not more than 30 degrees, but 
for angles varying from 30 to 45 they claim less 
wear on their tires by the latter construction. 
The exact arm for the angles in a steering gear 
of this nature will depend largely on the wheel¬ 
base of the car as well as the difference between 
the steering pivots A and B. 

Steering Gear—Types of. Fig. 314 shows a 
sectional view of the nut and segment type of 
steering gear, in which there is a worm D on the 
steering column that engages with the nut E. 
On the front or gear face of the nut is a rack F 
which meshes with the sector G, so that as the 
steering wheel is turned right or left the nut is 
raised or lowered and the requisite movement 
imparted to the radius rod H. In certain screw 
and nut steering gears the sector is not required, 
the construction being a screw on the steering 
column on wdiich works the internally threaded 
nut, and on either side of this nut are trunnions 
with links which connect with the axis carrying 
the radius arm. 


642 


The Automobile Handbook 


Steering Gear—Lost Motion in. If the gear 
is of the worm and sector type it may be that 
these two elements are.not held in the proper 
relation to each other. Fig. 315 shows a dia¬ 
gram of this type of gear, and illustrates plainly 
the point where lost motion will be of the great¬ 
est detriment. When the wheel is turned, if 
there is the slightest, end play, the wheel shaft 



Fig. 315 

will respond, but the geared sector will not, 
until all the end play is taken up, and as 
strains come on from the road wheels, the sec¬ 
tor will rotate to and fro, causing the shaft of 
the steering wheel to reciprocate and thus al¬ 
low the road wheels to wobble. To overcome 
tnis it is necessary to replace the thrust washer, 
if there be one, and if necessary, introduce a 







The Automobile Handbook 


64S 


washer, made of phosphor bronze, of suitable 
thickness to take up all the end play of the 
steering wheel shaft. 

Some lost motion will follow if the worm is 
not set on the pitch line, in its proper relation 
to the sector; this will be true if the bushings 
are worn, and when a new thrust washer is 
made and fitted into place, if the lost motion is 
still greater than is desired, the only thing re¬ 
maining is to replace the bearing brasses. When 
the gear is dissembled it will be possible to di¬ 
mension the same, and determine by measure¬ 
ment if there is any great amount of journal 
wear, thus rendering the task less troublesome, 
since the brasses may be replaced without wait¬ 
ing to determine the remaining lost motion 
through actual trial. 

As a rule, it will be found that the lost motion 
is due to end play, just as the illustration shows, 
and not to worn-out journal brasses on which 
the wear is far less than it is in thrust. If the 
gear is irreversible, or nearly so, as it is in many 
automobiles, a little lost motion is to be ex¬ 
pected owing to the smallness of the angle of 
the worm, which can only be irreversible if the 
angle is such that a little lost motion will be 
present and unavoidable. 

Care of Steering Gear. The steering gear 
is a very important part of the car, and, as the 
safety of the occupants may be endangered by 
any binding, the autoist should give it even 
more careful attention than the other parts. 


644 


The Automobile Handbook 



Fig. 316 

Worm and Sector of Steering Mechanism 

The gear should be taken down, given a thor¬ 
ough cleaning and examined for possible wear. 










The Automobile Handbook 


645 


In case the steering action is stiff and the wheel 
turns hard, the ball joint may be out of adjust¬ 
ment due to wear; the steering link may be 
bent, or the cause may be insufficient lubrica¬ 
tion. If there is any considerable amount of 
backlash, the cause may be looked for in the 
joints of the levers, in the swivel pin, or in 
loose bearings. 

Strength of Metals. The strength of a metal 
is most often given in terms of the ultimate ten¬ 
sile strength. This is the load per square inch of 


TABLE 13 


TENSILE STRENGTH AND ELASTIC LIMIT OF METALS 


Kind of Metal Tensile Strength Elastic Limit 


Aluminum, cast. 

Brass, cast. 

“ , rolled . 

“ , wire. 

Bronze, aluminum. 

44 , manganese. 

“ , phosphor . 

Copper, cast. 

Iron, cast. 

“ , malleable. 

“ , wrought. 

Lead. 

Steel, carbon, soft. 

“ , carbon, .15-.30%.. 
“ , “ ,30-.40%.. 

“ , 44 f hard. 

“ , cast average. 

44 , forgings. 

“ , nickel. 

44 , vanadium. 

Tin. 

Zinc . 


10,000- 16,000 
12,000- 18,000 
30,000- 40,000 
60,000- 75,000 
80,000-100,000 
60,000- 80,000 
35,000- 40,000 
20,000- 35,000 
14,000- 30,000 
25,000- 45,000 
35,000- 50,000 
1,500- 2,500 
50,000- 60,000 
60,000- 70,000 
70,000- 90,000 
90,000-110,000 
60,000- 80,000 
70,000- 90,000 
80,000-100,000 
60,000-230,000 
3,000- 5,000 
5,000- 6,000 


4,000- 6.000 


50,000- 70,000 
25,000- 35,000 
20,000- 22,000 
10,000- 15,000 
6,000- 20,000 
10,000- 20,000 
20,000- 25,000 

20,000- 30,000 
30,000- 40,000 
35,000- 40,000 
35,000- 40,000 
30,000- 40,000 
35,000- 45,000 
40,000- 75,000 
40,000-150,000 























646 


The Automobile Handbook 


section at which the metal lengthens and does 
not come back to its original form. A measure 
of strength that is fully as valuable in pratical 
work is the elastic limit, this being the maximum 
load that the metal will carry, possibly with 
bending or slight elongation, but after which 
it will resume its original shape. Another qual¬ 
ity of a material by which its strength is some¬ 
times measured is the compressive strength in 
pounds per square inch of section, this being the 
load that the material will carry without perma¬ 
nent deformation, when this load acts in a direc¬ 
tion which tends to crush the material being 
tested. 

In Table 13 are given the tensile strengths 


Thread 

TABLE 14 

SCREW THREAD STANDARDS 

Threads per Inch 

Tap Drill 

Size 

U. S. S. 

S. A. E. 

Size 

1/4 .... 


28 

7/32 

5/16 .... 


24 

17/64 

3/8 _ 


24 

21/64 

7/16 . 


20 

3/8 

1/2 . 


20 

7/16 

9/16 _ 


18 

1/2 

5/8 . 


18 

9/16 

11/16 . 


16 

39/64 

3/4 . 


16 

43/64 

7/8 . 


14 

25/32 

1 . 


14 

29/32 

1% . 


12 

1 1/64 

m . 


12 

1 9/64 

i% . 


12 

1 17/64 

iy 2 . 


12 

1 25/64 


















The Automobile Handbook 647 

found under average conditions, also some of 
the elastic limits of the metals commonly used 
in automobile construction. 

Threads, Screw. In Table 14 are given the 
number of threads per inch for the various diam¬ 
eters of screws in the United States Standard 
thread (Sellers) and also for the standard of 
the Society of Automotive Engineers (S. A. E.). 

Tires, Care and Repair. Aside from gaso¬ 
line the greatest expense in the upkeep of a 
motor car is the tires, and much of the present 
excessive tire wear may be reduced with reason¬ 
able precaution and care. There are ten com¬ 
mon tire diseases, as follows: wheel out of align¬ 
ment, under-inflation, use of anti-skid chains, 
skidding, running wheels in car tracks, neglect 
of casing repairs, tread cuts, running in ruts, 
stone bruises, use of inside protectors on new 
tires. 

When a tire is on a wheel which is out of 
alignment the result is that the tire is scraped 
across the surface of the road and the resulting 
friction causes the tire tread to wear rapidly. 
The action of the tire on the road is crosswise 
at the same time that the,tire revolves with the 
wheel. Thus the tire receives its usual wear 
plus the wear due to the scraping. The tread 
of a tire which has been run on a wheel out of 
alignment presents a rough appearance, that 
which would be given it were the tire held 
against an emery wheel for a while. Sometimes 
the fabric shows in places, and this is especially 


648 The Automobile Handbook 

true of wheels which are wobbly. It is advis¬ 
able to line up the wheels of a motor car about 
every three months, and if onb is found which 
does not run true, the condition should be cor¬ 
rected immediately. 

Perhaps as much harm is done by running a 
tire under-inflated as by anything else. Under¬ 
inflation, as the name implies, means that the 
tire is running with insufficient air pressure. 
Such a tire appears usually with a series of hilly 
blisters running around the tread. The blisters 
are caused by the separation of the fabric from 
the tread due to the excessive heat generated in 
an under-inflated tire. With insufficient air the 
flexing of the walls of the tire causes heat to 
be generated and this heat acts on the cement 
between the tread and fabric and in a short time 
the two separate, causing a blister to appear. 
Even in the summer a tire should not be run 
under-inflated. The common version is, that if 
the ordinary pressure is 80 pounds, a reduction 
of possibly ten pounds is made for summer 
weather. The belief is that the heat of the at¬ 
mosphere will soon raise the temperature of the 
air in the tire and thus cause the pressure to in¬ 
crease to the proper point. This practice is not 
advisable, as there is undue wear on the tire 
while the pressure is being increased by the rise 
in temperature, and also because the pressure 
will drop as soon as the tire cools. The cure 
for under-inflation need hardly be stated. Keep 
the tires inflated to the pressure specified by 


The Automobile Handbook 64D 

the maker, which is usually 20 pounds per inch 
of cross-section. Thus, a 4-inch tire should carry 
80 pounds pressure. It matters not if the press¬ 
ure is a little more, but it does if the pressure 
is less than that for which the tire is designed. 
A tire guage, such as is sold for one dollar, 
should be one of the important instruments in 
the motorist’s tool kit. 

When anti-skid chains are applied to the tire 
too loosely or too tightly, the result sometimes 
is a cut tread. These chains should be placed 
on the tire so that they fit snugly and then no 
material tire wear will result. 

' Running a wheel in car tracks may soon cause 
the sides of the tire to become chafed, and in 
some instances the wear is so much that the 
tread loosens at the sides and begins flopping 
around. The same appearance may result if 
the car is driven very close to the curb and the 
side of the tire made to scrape the stone. 

Little cuts in the casing often result in the 
casing being unfit for use in a short time. When 
a small cut appears and the tire is operated, 
dirt and water get underneath the tread. This 
dirt works its way around the tire under the 
tread with the result that the tire is soon loose. 
Water, as everyone knows, is detrimental to rub¬ 
ber, and more so to the fabric. Fabric begins 
to rot in the presence of water. The small cuts 
may be plugged with mastic. 

Often a cut appears in the tread and an in¬ 
spection finds that the fabric is injured also. 


650 The Automobile Handbook 

In such an instance the blowout patch is the 
first resort. The patch, if wrongly applied, 
sometimes becomes wedged in the fabric cut and 
in this way hastens a blowout. The best way 
to treat a tire with a reasonably large tread cut 
is to have the cut vulcanized immediately. In 
fact, even small cuts should be vulcanized at the 
first opportunity. The owner may say that the 
cost of having the tire vulcanized every time it 
is cut is expensive. It may seem expensive at 
first, but the saving in tire wear and repair later 
overbalances the comparatively small cost of 
vulcanization. 

In the fall especially country roads present a 
mass of hardened ruts which play havoc with 
tires. These hard indentations house the tire 
for a while and then the driver will go over the 
rut. The driving in and out of these ruts cre¬ 
ates a condition which puts a tire in the rut- 
worn class. The sides of the tread begin to show 
rapid wear and sometimes the wear is great 
enough to cause a weak spot in the tread, with 
the result that the tire blows out. 

Stone bruises cause a great percentage of tire 
failure. When a tire runs over a stone, one as 
big a man’s fist, there is a possibility of the 
fabric becoming broken. A broken fabric soon 
causes a blowout, so it remains for the driver 
to prevent as far possible running over such 
stones. Small stones sometimes present sharp 
edges which cut the tread and thus make an 
entrance for dirt and water. Stone bruises are 


The Automobile Handbook 651 

hardly visible from the outside, as the condition 
is one of a fabric break, as mentioned above. 
The result of a stone bruise may be seen by ex¬ 
amining the inside of the casing, which will 
show clearly that the fabric is injured. 

Some makers state that the use of inside pro¬ 
tectors on new tires is not advisable, as these 
appliances create an undue amaount of heat in 
the tire and thus hasten wear. For old tires the 
inside protector is perhaps the best accessory 
marketed for lengthening tire life. Some own¬ 
ers have obtained as much mileage with old tires 
and inside protectors as they have from new 
tires operated without protectors. 

Tire Vulcanizing. Absolute cleanliness is 
necessary in all vulcanizing work. No matter 
how good a vulcanizer you have or what kind 
of repair stock you use, the smallest amount of 
oil, grease or dirt will greatly impair the work. 
Therefore clean every repair thoroughly with a 
cloth or brush dipped in clean gasoline and 
roughen the point of repair with a rasp or 
coarse sandpaper while still wet. 

Tires must be dry before beginning work on 
them, otherwise a porous patch will result. If 
you think, for any reason, that the canvas in 
the casing is even slightly damp, clamp the 
vulcanizer loosely over the tire for ten or fifteen 
minutes before applying the first coat of cement. 
Interpose a piece of waste or something of the 
sort between vulcanizer and tire to permit the 
escape of moisture. 


652 The Automobile Handbook 

It takes from fifteen to twenty minutes to 
vulcanize a layer of Para one-sixteenth of an 
inch thick if the thermometer is kept at 265 
degrees, and five additional minutes for each 
additional sixteenth of an inch. Vulcanization 
will occur equally well at all temperatures be¬ 
tween 250 degrees and 275 degrees. The lower 
temperatures require more, and the higher tem¬ 
peratures less time than stated above. 

Inner tube punctures. Clean the tube thor¬ 
oughly with gasoline and coarse sandpaper, for 
at least an inch all around the hole (be careful 
not to get gasoline inside the tube) ; then wipe 
with a cloth moistened with gasoline. When 
the gasoline has'evaporated cement the edges of 
the hole and apply a thin layer of cement to 
the tube for three-quarters of an inch on each 
side of the hole. Let the cement dry until 
the gasoline has all evaporated and the cement 
is solid enough to resist the touch. * 4 Tacky’* 
is the usual word. Apply a second coat and let 
dry as before. 

If a small hole, fill even with the surface of 
tube with layers of Para rubber cut the size of 
the hole, taking care that the Para sticks all 
around the edges. If a simple puncture, place 
a narrow strip of Para rubber over the end of 
a match and insert it into the hole. Cut off 
what protrudes outside the tube. Cut a patch 
of Para one-eighth larger than the hole or punc¬ 
ture and apply over same. Then cut another 
patch one-half inch larger than the hole and 


The Automobile Handbook 653 

apply over the first. Cover and apply vulcan- 
izer. 

Repairs of this sort are to be vulcanized for 
fifteen or twenty minutes at 265 degrees. 

Inner tube cuts and tears. Clean as directed 
both inside and outside of tube; coat edges of 
cut and inside and outside of tube with cement 
and let dry. The cement should extend three- 
fourths of an inch back from the cut. 

Cut a strip of Para rubber as wide as tube 
is thick and stick on edge of cut; cut a strip 
one-half inch wide of Para rubber cured on one 
side, place it inside of tube under tear with 
cured side down, bring edges of tear together 
and stick them down to this strip. If you do 
not have any of the Para cured on one side 
regular Para may be used after cementing a 
piece of paper to inside of tube opposite the cut 
to prevent patch from sticking to opposite side. 

Apply another strip of Para rubber one-half 
inch wide on the outside of the repair. Vul¬ 
canize for twenty-five minutes. 

The first step in making a casing repair is. 
just as in the case of all tire work, to thoroughly 
clean the point of repair. Apply from one to 
three layers of cement, allowing each to dry. 
If the canvas is exposed, as in a scalp cut, put 
on enough cement to fill the pores of the canvas 
and leave a smooth surface when dry. Fill the 
hole not quite level with surface with Para rub¬ 
ber. The best results are obtained when casing 
repairs are slightly concave. If filled too full, 


C54 The Automobile Handbook 

the rubber will expand and flow over onto the 
unprepared surface in a thin film that will soon 
peel up and cause trouble. Moreover, a pro¬ 
truding patch will receive more than its share 
of hammering and will undoubtedly split open. 

Tonneau. The name or term used in connec¬ 
tion with the rear seats of a motor car. Liter¬ 
ally the word means a round tank or water 
barrel. 

Torsion Rod. When the manner in which 
the power is transmitted from the change-speed 
gear to the rear axle on the shaft-driven car is 
considered, it will be apparent that the turning 
of the shaft imposes a twisting strain on the 
whole rear end of the car, and that if it were not 
for the frame, and the weight of the car on the 
ground, there would be a tendency to revolve 
the rear of the chassis around the shaft, rather 
than to -turn the wheels. But it would be bad 
practice to permit this strain to fall on the frame 
and hence the office of the torsion rod, which is 
designed to prevent its reaching that member. 
On cars that are not provided with independent 
torsion rods, it will be found that the housing 
of the propeller shaft has been made corre¬ 
spondingly stronger, and that its support has 
been designed to enable it to act in this double 
capacity. This represents a simplification of 
design that will be found on quite a number of 
cars, as it eliminates a part exposed to mud and 
dirt. 

Traction of Driving Wheels. A horse which 


The Automobile Handbook 


655 


exerts a pull of about 375 pounds continuously 
for an hour and goes a distance of one mile in 
an hour is working at the rate of one horse¬ 
power. If for any reason the horse is unable to 
exert as much as 375 pounds pull when going 
at the rate of one mile per hour, he is thereby 
prevented from working at the rate of one 
horsepower. 

The same rule applies to a motor car. When 
the road is not slippery there may occur a con¬ 
dition which does not appear with horse trac¬ 
tion ; that the tires fail to adhere to the ground 
owing to insufficient weight on the driving 
wheels. In such a case it is impossible for the 
motor-car to exert a push of 375 pounds with¬ 
out skidding the wheels, and thus it would be 
impossible for it to work at the rate of one 
horsepower. With underpowered motor-cars 
this difficulty does not occur, but to develop 10 
horsepower at the rims of the driving wheels 
while covering the ground at the rate of one 
mile per hour, the car must exert a push on the 
road of 3,750 pounds. This is, on touring cars 
of ordinary weight, impossible, because the 
weight on the driving wheels is invariably less 
than 3,750 pounds, while the adhesion with the 
road is only a fraction of the weight on the rear 
wheels. As the speed rises, however, the push 
necessary for the development of 10 horsepower 
goes down until at 10 miles per hour a push of 
375 pounds means 10 horsepower. 

Thus a 40 horsepower car, if it could start 


656 


The Automobile Handbook 


work with the activity of forty horses, would, 
while it was moving at one mile per hour, exert 
no less a push than 40 x 375, which is equal to 
15,700 pounds. This tremendous push is ren¬ 
dered impossible by the fact that the wheels of 
a car weighing 2,000 pounds only grip the 
ground enough to exert about 750 pounds push. 
Beyond this point they will skid. 

This shows that a high-powered car, when the 
car is moving slowly, cannot develop its full 
power unless the road wheels are capable of ad¬ 
hering to the ground sufficiently to transmit 
this power. As a rule only about 0.6 of the 
weight of the car is on the driving wheels, and 
of that only 0.625 is available for the adhesion 
(owing to the coefficient of friction between 
rubber and road being 0.625). So a 10 horse¬ 
power car weighing 2,000 pounds cannot exert 
its full power when the car is starting, nor until 
it is traveling at 5 miles per hour. 

It would be wrong to contend that on all 
cars having the weight distributed as at pres¬ 
ent, a 60 horsepower motor is useless, but it is 
needless to say that the output of such a motor 
is not availabe at starting or at any speed 
under 30 miles per hour, although the whole 
power is more needed then than at any other 
time. The remedy which suggests itself is by 
using all the adhesion of the car, that is, to 
drive with all four wheels. 

Transmission. See Change Speed. 


The Automobile Handbook 657 

Trouble Location. See Compression, Ex¬ 
haust, Knocking, Pounding, Preignition, Re¬ 
pairs, Self Firing, etc. 

Unit of Heat. The heat unit or British ther¬ 
mal unit (B. T. U.) is the quantity of heat re¬ 
quired to raise the temperature of one pound 
of water one degree, or from 39° to 40° F., and 
the amount of mechanical work required to pro¬ 
duce a unit of heat is 778 foot pounds. There¬ 
fore the mechanical equivalent of heat is the 
energy required to raise 778 pounds one foot 
high, or 77.8 pounds 10 feet high, or 1 pound 
778 feet high. Or again, suppose a one-pound 
weight falls through a space of 778 feet or a 
weight of 778 pounds falls one foot, enough 
mechanical energy would thus be developed to 
raise a pound of water one degree in tempera¬ 
ture, provided all the energy so developed 
could be utilized in churning or stirring the wa- 
*;er. 

Vacuum Fuel Feed. See Fuel Feed, Vacuum. 


658 The Automobile Handbook 

% 

Valves. There are two valves, one inlet and 
one exhaust, for each cylinder of a four cycle 
internal combustion engine. Some engines of 
recent design provide four valves in each cylin¬ 
der, two of each kind. Four types of valves are 
in use; the poppett, the sleeve, the rotary and 
the disc. 

Typical designs of poppett valve installations 
are shown in Figures 317 and 318. Both valves 
shown are of the mechanically operated type, 
the only method of operation at present in use. 
Such valves are opened by means of cams 
mounted on the cam shaft of the engine and 
are closed by the force of coiled springs placed 
around the lower part of the valve stem and 
attached to the end of the stem. 

There are three locations for the valves with 
reference to the combustion space of the engine 
cylinder, all methods being in more or less com¬ 
mon use. The most popular location is in plac¬ 
ing both inlet and exhaust valves in a single 
pocket at one side of the combustion space, such 
a design going by the name of an “L” head 
engine. In other cases the exhaust valve is in 
a pocket at one side with the inlet in a similar 
pocket on the other side, this engine being called 
a “ T ” head. Overhead valve engines are made 
with both valves opening into the top of the 
combustion space and operated by some form of 
rocker arm mechanism actuated from the cam 
shaft through vertical push rods. Overhead 


The Automobile Handbook 


659 


▼alve engines may also be made with the cam 
shaft carried above the cylinders. 

Pocketed valves can be exposed and removed 



Fig. 317 Fig. 318 

__ . Intake Valve, 

Inclined Poppett Valve poppett Type 


through screw caps placed above the head of 
each valve and in the top of the pocket. Over¬ 
head valves are carried in cages which form the 














































660 


The Automobile Handbook 


valve seat, the cage then being fastened into 
the head of the cylinder. 

Sleeve Valves. During the last few years 
there has been placed on the market a type of 
engine that does not have poppett valves, but 
which has a type of valve known as a 4 4 Sleeve 
Valve.” See Engine, Sliding Sleeve Type. 

Sleeve valves are made by placing two sliding 



Fig. 319 

Sliding Sleeve Valves 


sleeves between the piston and the cylinder 
walls, Fig. 319. These sleeves are shaped like 
a section of tubing and are about an eighth of 
an inch thick. There are holes or slots cut 
through the sleeves near the top, that is, in the 
part of the sleeve nearest the cylinder head. 





























The Automobile Handbook 661 

The holes, or “ports” as they are called, are 
placed so that when the sleeves are placed in a 
certain position the holes are opposite each, 
other. When they are opposite each other they 
will let the mixture through into the cylinder or 
let the burned gas out into the exhaust pipe, 
depending on which thing it is necessary to do. 

The lower ends of the sleeves connect with 
small connecting rods which are worked up and 
down by eccentrics on the shaft that takes the 
place of the cam shaft. These small connecting 
rods move the two sleeves up and down so that 
when the piston is ready to start down on 
the inlet stroke two of the openings come oppo¬ 
site each other, one opening in each sleeve. 
These two openings are brought opposite the 
opening that goes to the carburetor at the same 
time they are opposite each other so that the 
fresh mixture can be drawn into the cylinder. 

After the piston passes bottom center the 
sleeves are moved so that the openings are not 
opposite each other or the opening to the car¬ 
buretor and the fresh gas is shut off. 

When the piston is most of the way down on 
the power stroke two ports on the other side of 
the sleeves, one opening in each sleeve, are 
brought opposite each other, and at the same 
time opposite a hole that opens into the exhaust 
pipe so that the burned gas can get out of the 
cylinder. After the piston finishes the down 
stroke, goes up on the exhaust stroke, and is just 
past top center, the two openings are moved so 


662 The Automobile Handbook 

that they close the hole into the exhaust pipe 
and then the inlet openings come opposite each 
other again. 

These sleeves are adjusted to open and close 
at just the right time by adjusting the length 
of the small connecting rods. 



Fig. 320 

Engine Having Single Rotary Valve 

The opening and closing of the ports should 
come simultaneously with the opening and clos¬ 
ing of the inlet and exhaust valves in a poppett 
valve engine. 

Rotary Valves. Other engines are made 
without either poppet or sleeve valves but with 
a type of valve called a ‘‘Rotary Valve.” 
















The Automobile Handbook 663 

Rotary valves, Figs. 320 and 321, are made 
by having a long round shaft run along the 
side of the cylinders near the cylinder heads. 
Holes are bored through this shaft so that the 
holes come opposite openings into the cylinder 
or combustion space and at the same time open 



Fig. 321 

Engine With Separate Rotary Valves 

into the pipe leading to the carburetor or to the 
exhaust pipe, according to the position the pis¬ 
ton is in and the stroke it is making. 

This long shaft or valve is set in a position to 
open the inlet holes at the same time as the 
inlet valves should open in a poppet valve 










664 


The Automobile Handbook 


motor, to close the inlet holes at the time tho 
inlet valves should close, and to open and dost 
the exhaust holes at the same time as the ex- 
haust valves should open and close in a poppett 
valve engine. 

The rotary valve is driven from the crank 
shaft by gears or chains so that it turns half as 
fast as the crank shaft, just the same as the cam 
shaft would turn. 

Disc Valves. There are still other engines 
made with a type of valve known as a “ Rotary 
Disc Valve.’’ These valves are in the shape of 
a piece of round iron as large around as the 
top of the piston and about a quarter inch thick. 
They are placed on the top of the cylinder and 
fastened to gears so that they rotate or turn 
around. 

Holes are cut through the disc so that they 
come opposite holes cut through the cylinder 
head. Some of these holes connect with the 
pipe that goes to the carburetor and others con¬ 
nect with the exhaust pipe. 

The discs are made to turn so that the inlet 
holes and exhaust holes are opened and closed 
at the same times as the inlet and exhaust 
valves are opened and closed on a poppett valve 
motor. 

All of the matter pertaining to valves on the 
following pages refers to the poppett type and 
covers the subjects of timing, clearance, grind- 
ing, etc. Subjects related to that of valves are 
treated under the head of Engine. 


The Automobile Handbook 


665 


Valve Clearance. A large number of motors, 
especially old ones, are unnecessarily noisy be¬ 
cause of superfluous clearance between the 
valve lifters and the valves, and a great part 
of the noise may be eliminated simply by the 
expenditure of a little time and care in reduc¬ 
ing this clearance to the minimum. Every valve 
cam, no matter what its shape otherwise may 
be, is tangential at the first and last portions of 
the valve’s movement. The sooner the valve 
takes hold of the cam on the lift, and the later 
it lets go on the descent, the slower will be the 



Pig. 322 

movement of the valve at these instants, and 
the less will be the shock both of the lifter on 
striking the valve stem, and of the valve head 
on meeting its seat. Fig. 322 shows this clearly. 
The tangent line A B starts at A, and during 
the arc D C the rise of the cam amounts only 
to a minute distance A D. 

The objection to an excessive clearance is not 



666 


The Automobile Handbook 


simply the vertical hammering, but the sidewise 
pressure imposed on the valve-lifters by the 
cams, particularly at the instant of opening the 
exhaust-valves. If it were possible to operate 
the valves with no clearance whatever, and if 
there were no lost motion, and if the whole 
mechanism were ideally rigid, the line of pres¬ 
sure of the cam at the instant could be said to 


t 



be vertical, and there would be no side thrust 
till the valve was off its seat and the pressure 
of the gases on the valve was partly equalized. 
As the matter actually stands, however, there is 
a side thrust which is considerably increased 
by unnecessary clearance, as comparison of 
Figs. 323 and 324 clearly shows. In Fig. 323 
there is no clearance, and. the tangent to 





The Automobile Handbook 


667 


the line of contact is horizontal. In Fig. 324 
there is a clearance, AB. The thrust acts at 
right angles to the tangent along the line C D, 
and if C E represents by its length the force 
required to overcome the pressure on the valve 
and the force of the spring, there is a horizontal 
thrust equal to D E. It goes without saying 



that valve-lifters thus adjusted will wear loose 
in the guides faster than they should. As the 
gas pressure on the valve head may amount to 
30 or 40 pounds per square inch the instant be¬ 
fore the valve is open, there is an evident tend¬ 
ency to wear a hollow in the cam at the pre¬ 
cise point where it starts the exhaust valve from 
its seat. Evidently, moreover, the smaller the 







668 


The Automobile Handbook 


clearance, the greater will be the leverage of 
the cam, and the smaller will be its wearing 
tendency. 

The precise amount of minimum clearance is 
hard to state arbitrarily. The thickness of a 
business card or about 10-1,000th of an inch is 
ample allowance for the expansion of valve 
stems for the average length. 

Valves—Lead of. The higher the speed of the 
motor the greater the necessity for giving both 
the exhaust, and the inlet valves what has come 
to be known as a “lead,” in that they open 
before the completion of the particular part of 
the cycle that they are intended to perform. It 
must be borne in mind that time is required to 
set a thing in motion and to stop it, regardless 
of its form or weight, and this is true of a gas, 
which has inertia the same as other substances. 
Further, an appreciable period, though very 
short indeed, is required for the creation of the 
vacuum in the cylinder. The gas does not rush 
into the combustion chamber the moment the 
inlet valve opens; the piston must have traveled 
downward a bit before this takes place and the 
column of gas then rushing in attains an in¬ 
creasing velocity as the piston approaches the 
lower center. 

Valve Timing. Before proceeding with the 
operation of valve timing, the proper clearance 
between the ends of the valve stems and the 
operating mechanism driven, from the cam shaft 
should be secured. 


The Automobile Handbook 


669 


The time or point during the engine cycle and 
during the revolution of the flywheel at which 
the valves open and close is specified in degrees 
of the circle measured on the rim of the fly¬ 
wheel. One complete circle, or the entire dis¬ 
tance around the rim of the wheel, equals 360 
degrees. Therefore, one stroke of the piston, 
being one-half of a full revolution of the fly¬ 
wheel, equals 180 degrees. The inlet valve will 
open during the first half revolution of the fly¬ 
wheel, or during the first 180 degrees on the 
rim of the wheel. During the next half revo¬ 
lution, the compression stroke, neither of the 
valves are open, and likewise, on the third, 
power stroke, both valves are closed. During 
the fourth half revolution, the exhaust stroke, 
the exhaust valve is open. Because of the fact 
that the valves open and close somewhere near 
either the top or bottom of the several strokes, 
their opening and closing positions are specified 
in the number of degrees before or after the 
top center, this being the point at which the 
piston is at the exact top of its stroke, or else 
the time is specified as before or after bottom 
center, this being the point at which tht piston 
is at the exact bottom of its stroke. 

The valve action for any one cylinder of a 
four cycle engine is shown in Figures 325 to 
328. In Figure 325 is shown the beginning of 
the inlet stroke with the piston at top center 
and with the inlet valve about to open. The 


670 


The Automobile Handbook 


opening of the inlet valve is generally made to 
occur from 2 to 10 degrees after top center. 

In Figure 326 is shown the position of the 
valves and cams at the beginning of the com¬ 



pression stroke with the inlet just closing. This 
closing point is usually frpm 20 to 40 degrees 
after bottom center, allowing the inrushing gas 
plenty of time to fill the cylinder. 






















The Automobile Handbook 671 

In Figure 327 is shown the end of the power 
stroke with the exhaust valve starting to open 
This opening should occur from 40 to 75 de¬ 
grees before bottom center so that the burnt gas 
will have an opportunity to start passing out in 



Fig* 326 

time to make a fairly complete exhaustion and 
avoid back pressure during the following up¬ 
ward stroke of the piston. 

In Figure 328 is shown the end of the exhaust 
stroke with the exhaust valve closed, this closing 





















672 


The Automobile Handbook 


taking place just before the opening of the inlet 
valve for the ensuing intake stroke, or, in some 
high speed engines, the exhaust valve may re¬ 
main open for two or three degrees after the in¬ 
let starts to open. 



The time during which the valves are open 
and closed during the four strokes is shown in 
Figure 329. From this drawing it will be evi¬ 
dent that the inlet stroke, measured by the valve 
opening time, lasts from 6 degrees after top 













The Automobile Handbook 


673 


center to 30 degrees after bottom center, or a 
total of 204 degrees. The compression stroke 
lasts from 30 degrees after bottom center to top 
center, at which time the piston starts down 
again, making a total of 150 degrees. The 



power stroke, presuming complete ignition to 
take place at top center, lasts from this point 
to 50 degrees before bottom center, or a total 
of 130 degrees. The exhaust stroke, longest of 
all, lasts from 50 degrees before bottom center, 


















674 


The Automobile Handbook 


all through the up stroke, and until 5 degrees 
after top center, making a total valve opening 
time of 235 degrees. 

The examples given represent only average 





practice and it should be understood that the 
best valve setting for any one engine may be 
found by inquiry from the makers of the car or 
engine, or from a study of their instructions. 








The Automobile Handbook 675 

In many cases the points of opening and closing 
will be found marked on the rim of the flywheel. 

Valve Grinding. To grind a valve pro¬ 
ceed as follows: First loosen the lower end of 
the valve spring from the lower end of the valve. 
This may be held by a number of different de¬ 
vices such as washers with pins under them, or 
grooves cut in the valve steam into which a 
washer slips. To loosen the spring it must first 
be pried up from the bottom, that is, so the end 
of the spring is held away from the end of the 
stem. This may be done by a special valve 
spring lifter or the repairman can make a forked 
lever so that the prongs fit on each side of the 
stem and lift the spring by resting the lever 
on some solid piece. Sometimes the spring can 
be lifted by taking a common screwdriver and 
using it to pry with. Before the spring can be 
raised, however, the cap that covers the head of 
the valve must be removed or at any rate the 
head must be reached. Now take a screwdriver 
or hammer handle or a piece of wood and wedge 
it into the valve pocket so that the head of the 
valve cannot lift. If this was not done the 
whole valve would lift when you pried up on the 
spring. 

After the spring is pried up out of the way 
remove whatever locking device was holding it 
and then the valve may be taken out of the hole 
above the valve head by letting the stem slip 
through the spring and locking parts. You can 
now examine the face and seat and you will 


67G The Automobile Handbook 

probably find them pitted. Also examine the 
stem, and if it is dirty or covered with soot 
(called carbon in the automobile business), it 
should be scraped clean with a knife blade or 
some sharp instrument. There must be no ridges 
on the valve stem that might keep it from seat¬ 
ing the valve properly. 

A valve stem must never be oiled or greased 
under any conditions. They are designed to 
work dry. 

The valve is ground by placing some cutting 
material between the seat and face and rubbing 
them together. Yalve grinding material may 
be made by taking emery powder of a fine grade 
and mixing it with enough engine lubricating 
oil to make a rather thin paste, or it may be 
made by mixing the emery with lubricating oil 
and kerosene. It may also be made by mixing 
powdered glass with a thin oil into a paste, this 
being used mostly for finishing the operation. 
If a very fine fit is desired a paste can be made 
with crocus powder and oil. A rather coarse 
paste is used at first if the surfaces are badly 
pitted and the finer, smoother pastes are used 
for finishing. 

After making the paste take a cloth (not a 
piece of waste), tie a string to it and stuff the 
cloth into the opening from the valve pocket to 
the combustion space. This is to keep the grind¬ 
ing material out of the cylinder, where it would 
do great harm. 

On the top of the valve head you will find a 


The Automobile Handbook 677 

slot for a screwdriver or else some holes that 
take the end of a special fork-shaped tool. 
These let you turn the valve face on the seat, 
and you will need a tool that fits the particular 
valve head you wish to work with. You will 
also need a small can of gasoline or kerosene 
handy so that the grinding compound may be 
washed from the valve and seat. 

The operation of valve grinding consists of 
placing a small amount of the grinding com¬ 
pound evenly on the face but not very thick. 
What you can easily pick up on the tip of a 
pocket knife blade is plenty at one time. The 
valve is now placed in the cylinder or part that 
it came out of so that the face rests on the seat. 
Now take the tool that turns the valve and turn 
the valve about half way around and then back 
again. Do this several times. Do not use much, 
pressure as the pressure forces the grinding 
compound from between the face and seat and 
makes the work slower. 

After making several half turns the valve 
head must be raised and turned to a new posi¬ 
tion while it is not touching the seat, and then 
the operation is repeated. If you do not raise 
the valve from the seat every few half turns you 
will make ridges on the face arid spoil the job. 
Also, if you turn the valve round and round 
without reversing the motion and raising it you 
will spoil the work. In order to raise the valve 
from the seat every once in a while you can 
take a light spring that fits around the stem and 


678 The Automobile Handbook 

place it on the valve stem just under the head. 
This spring should rest on the metal of the cyl¬ 
inder at its lower end and hold the valve about 
a half inch off the seat. When you press on 
the valve grinding tool the valve will be pressed 
down onto the seat, but when you release the 
pressure it will raise again and you can turn 
to a new position without pushing up on the 
stem from below. 

The vS,lve must be ground for a few minutes 
and then washed off and carefully examined. 
When the face and seat are a clean even light 
gray all around and have no marks or pits or 
rings at any point the job is finished. 

The next thing to do is to test the valve for 
tightness. This can be done by placing pencil 
marks at short distances all around the face and 
then pressing the valve down and turning it 
once around. If the marks.are all off the face 
it will be tight. You can also pour gasoline or 
kerosene on top of the valve and watch for it to 
run down the stem. If it does not leak through 
it is tight. 

Now wash every trace of grinding material 
from the valve and the seat and valve pocket 
and replace the valve with the spring and the 
valve cap. 

Pitted Valves. A valve in a pitted con 
dition causes bad compression, and the exhaust- 
valve should be ground occasionally. After 
grinding the exhaust-valve be sure that there 
is ample clearance between the valve and the 


The Automobile Handbook 679 

lifter. It should have not less than one hun¬ 
dredth of an inch, otherwise when the valve be¬ 
comes hot it will not seat properly, poor com¬ 
pression being the result. In grinding a valve 
there is no occasion to use force, and the grind¬ 
ing should be done lightly, the valve being 
lifted from time to time so that any foreign 
substance in the emery will not cut a ridge in 
the seat, or the valve itself. After grinding the 
valve always wash out the valve seat with a 
little kerosene, and be careful that none of the 
emery is allowed to get into the motor cylinder. 

A good mixture for grinding valves may be 
made by using fine emery and cylinder oil 
mixed in the form of a paste convenient to 
work with. 

Exhaust-Valve Sticking. Sometimes a mo¬ 
tor may suddenly stop from the failure of the 
exhaust-valve to seat properly. This may be 
due to the warping of the valve, through the 
motor having run dry and become hot, or it 
may be from the failure of the valve spring, or 
the sticking of the valve-stem in its guides. The 
valve should be removed, and the stem cleaned 
and scraped, or straightened if it requires it, 
until it moves freely in the guide, and the 
spring is given its full tension. If the valve 
still leaks so that the motor will not start or 
develop sufficient power, the valve will have to 
be ground into its seat. 


680 The Automobile Handbook 

Vulcanizing. See Tire Vulcanizing. 

Watt-Hour—Definition of. A current of one 
ampere fiowing in an electric circuit, with an 
electro-motive force of one volt, is equal to 
one volt-ampere or one watt. The voltage of a 
circuit, multiplied by the rate of the current 
flowing in~"amperes, gives the rate of work, or 
energy expended in watt-hours. 

It is oftentimes found that electric lamps for 
automobile lighting are rated according to their 
consumption in watts rather than directly in 
amperes. The number of candlepower secured 
from each watt consumed will vary according 
to the size of the lamp in candlepower, the 
material of which the filament is made and the 
type of bulb, whether vacuum or nitrogen. A 
small bulb with tungsten filament will use from 
1.10 to 1.25 watts per candlepower, and this is 
reduced until in the largest candlepower the 
rate is about 0.95 watts. The consumption with 
carbon filaments is about two and one-half 
times that with tungsten. Nitrogen bulbs use 
less current than the vacuum type. 

Welding—Autogenous. This process consists 
of welding, or, more correctly speaking, melt¬ 
ing together metals by means of the oxyacety- 
lene flame, the temperature of which almost 
rivals that of the electric arc, being 6,300 de¬ 
grees Fahrenheit. The facility with which it 
can be handled as compared with most other 
methods makes its commercial application com¬ 
paratively simple. The possibilities attendant 
upon the use of a flame of such high tempera- 


The Automobile Handbook 681 

ture can be realized when it is remembered that 
the melting point of steel is about 2,570 degrees 
and that of platinum, one of the most refrac¬ 
tory metals, is only 3,227 degrees Fahrenheit. 
Its chief field of usefulness is in combining such 
metal parts as would ordinarily be riveted, in 
welding small parts together, in repairing bro¬ 
ken or defective castings and for cutting metals 
of any nature or size that occasions demand. 

As it is possible to unite many dissimilar 
metals, and with a heat so localized that neigh¬ 
boring parts are not affected, autogenous weld¬ 
ing has already found an extensive application 
in motor car repair work. Broken crankcases 
or other parts can be united and made practi¬ 
cally as strong as new. The method of holding 
the pieces of a broken aluminum case, for exam¬ 
ple, is to clamp them into position temporarily 
while clay is packed around the parts and 
heated sufficiently to drive out the moisture, 
thus forming a solid support for the parts as 
well as a kind of mould. A series of holes are 
usually drilled at the crack, or the edges of the 
pieces are roughly beveled so, as previously ex¬ 
plained, the metal can be built up from the bot¬ 
tom. In some instances lugs or peculiar shaped 
projections may have been completely worn off 
or destroyed, when it becomes necessary to build 
up new ones with additional metal. In repair¬ 
ing a cracked water jacket, after the edges of 
the crack have been prepared, it is customary 
to use copper instead of iron wire for the filling 


682 


The Automobile EandoooK 


metal as it flows at a lower temperature and 
adheres very positively. In case there is dan¬ 
ger of warping, due to local expansion, the 
entire cylinder is heated before operating 
upon it. 

Wheels. The wood work of all wheels should 
be of selected grades of second growth hickory, 
or equally good growths of other hard woods. 
In the driving wheels the twisting moment of 
the motor is transmitted to the spokes of the 
wheels, and this torsion must be resisted by 
the wood at the miter, therefore, if the hub 
flanging is not clamped tight there is danger of 
the joints 4 ‘ working / 7 which will soon lead to 
something worse. When the hub clamping 
bolts are tightened up they should be so pinned 
that they will not turn with the nuts because 
if the bolts do turn it will be impossible to 
apply sufficient pressure, and the clamping ef¬ 
fort will be insufficient. Fig. 332 shows a hub 
in which the clamping bolts are prevented from 
turning by means of a triangular shaped exten¬ 
sion just under the bolt heads, which engages 
a slot in the flange. In this hub the flange is 
made integral with the brake drum, which also 
serves for the sprocket wheel, and the torsional 
effort is taken by integral metal at all points, 
thus relieving the wood work from shock. The 
nuts used on the clamp bolts shown in Fig. 332 
are castellated, although it is not necessary to 
use castellated nuts unless the flanges have to 
be removed, which in modern construction is 



























684 The Automobile Handbook 

the exception, rather than the rule. In ordi¬ 
nary practice if the wood is thoroughly sea¬ 
soned, plain nuts, if screwed up tight will hold 
without resorting to the method so common in 
shop practice of riveting the ends of the bolts 
over the nuts. The elastic nature of the wood 
will serve to hold the nuts in place. Regard¬ 
ing spokes, a certain symmetry of contour is 
necessary if they are to be machine made. Fig. 



330 shows a spoke in which all the advantages 
known to wheel making are embodied, and the 
depth of flanging is that which experience dic¬ 
tates as adequate. The dimensions of the spoke 
are shown in detail in the cut. The brake drum 
is bolted to the spokes at a considerable radius, 
thus eliminating excess strain on the wood 
work. 

The strength of the spoke depends in a large 
















685 



Fig. 332 

Section Through Rear Wheel with Combination Brake 
Drum and Inner Flange 

































































































































686 


The Automobile Handbook 


measure upon its thickness in the axle plane at 
the hub flange, which in Fig. 330 is 1% in. The 
second point of importance is at A, B, where 
the largest diameter is a)so 1% in., but in the 
plane of the wheel instead of the axle. At the 
tenon engaging the felloe, this spoke is 1% in., 
in its major diameter, which is the plane of the 



axle,- while in the plane of the wheel the minor 
diameter of the elliptical section is 1 3/16 in., 
which dimension prevails in this plane from 
point A, B, out to the felloe. In some types of 
spokes the section at the engagement of the fel¬ 
loe is round, and reduced gradually to the sec¬ 
tion at A, B. Fig. 331 shows a section of the 




















The Automobile Handbook 


687 


hub of another type of wheel, in which the 
radial depth of flanging is 2*4 in., and the axle 
thickness of the wood is 2% in. This wheel 
may be used on a 60 H. P. car, and will serve as 
a safe example of depth of flanging, as well as 
a guide in fixing the shear section of the spokes 
for stresses induced, when cars of great power 
skid, provided the wheel is not dished. Fig. 
333 shows the same spoke at its engagement 
with the felloe, indicating the manner in which 
the spoke is wedged into the felloe. 



Figure 334 shows the Schwarz type of wheel, 
indicating the method of overlapping the mi¬ 
ter, thus making it possible to true up the wood 
work independent of the hub. Fig. 335 shows 
a section of the hub, spoke and felloe of a 
dished wheel, and it will be seen that the felloe 
is not‘in the plane of the miter, and the dish of 
the wheel is outward. When a car is running 
at a comparatively high speed rounding a 
curve, the outet wheels are stressed in such a 














688 


The Automobile Handbook 


manner that the tendency is to set a dish in 
them exactly opposite to the dish given by the 
wheel maker. 

The shorter the spokes are,/the greater will 
the dishing have to be in order to insure that 
the spokes will be enough longer than the radial 



distance from the hub end of the spokes to the 
bearing against the felloe, to serve as members 
in compression, and the rim on the felloe will 
have to do the work. As the cut shows, the ex¬ 
cess length of spokes marked “difference,” 
represents the versed sine of the angle of the 
spokes. 







The Automobile Handbook 


689 


Wheel Rim Sizes and Types. In Figure 336 
are shown the sections of the three standard 
wheel rims which are designed to accommodate 
the three types of pneumatic tire bases. At the 
left is the plain clincher rim which is made in 
one piece and over which the tire base is forced 
into place. The plain clincher tire for use with 
this rim is made with its base soft enough to 
allow the necessary distension in applying. 



In the center is shown the quick detach¬ 
able clincher rim, often abbreviated “Q. D. 
Clincher/ ’ and which is designed to take a tire 
having a non-flexible base by the removal of the 
detachable ring from one side of the rim. At 
the right is shown the rim used with straight 
side tires which is similar in construction to 
that for the quick detachable clincher with the 







690 The Automobile Handbook 

exception of the shape of the flanges which are 
suited to the tire base. 

Wire Wheels. The development of the wire 
wheel has been very rapid during recent years. 
The invention of the wire wheel created a 
radical change in the method of load carrying, 
due to the fact that, instead of the compressive 
strain brought to bear upon a few spokes 
underneath the axle, as is the case with the 
ordinary type of wheel, there is a tensional 
stress on a large number of "wire spokes, and 
the weight is thus held in suspension by the 
wire wheel with its steel rim and steel wire 
spokes. 

Although the pneumatic tire is a great ab¬ 
sorber of jolts, if the wheel strike an obstruc¬ 
tion the shock of which is beyond the capacity 
of the tire to absorb, and if the wheel is fitted 
with rigid spokes, this shock is passed directly 
to the axle and from thence to the car springs, 
and unless these are equipped with efficient 
shock absorbers, the passengers are sure to 
feel the effects of rough riding. On the other 
hand the spokes of the wire wheel all act as 
a complex yet effective shock absorber, and 
in this way tend to reduce in a large measure 
the annoying effects of these vibrations. An¬ 
other advantage in connection with the use of 
wire wheels is that the wheel itself, owing to 
its construction and the nature of the material, 
acts as an effective tire cooler, which is not 
the case with the wooden wheel, for the 


The Automobile Handbook 691 

reason that the spokes of the latter do not 
tend to radiate the heat generated in the tire 
while running, consequently this heat must 
radiate from the tire and rim and the process 
is a very slow and ineffective one. Regarding 
the two important features of durability and 
lightness of weight, experience has demon¬ 
strated that the wire wheel compares favorably 
with the wooden wheel. It is claimed that the 
lightness of the wire wheel is an important 
factor in reducing the tendency to gyroscopic 
action, which is always present in wheels run¬ 
ning at high speeds. 

The number of spokes in each wheel and 
method of their attachment to the hub and 
the rim vary according to the ideas of Hie 
designers. In some types of wire wheels the 
rim only is demountable, while other types 
have all the functions of a demountable rim 
and a demountable wheel. The Lindsay twin 
wire wheel (a semi-sectional view of which is 
shown in Figure 337) is a notable example of 
the latter type. ^The component parts of the 
Lindsay wheel are assembled into two complete 
self-contained sections or units, hence its name. 
There are eighty spokes that connect the rim 
parts and hub parts together. The wheel as 
a whole is mounted on the inner fixed hub and 
interlocks with it, also interlocking with the 
web of the brake drum. The form of structure 
gives two rows of spokes laced in each side 
of the wheel, thereby taking care of the side 


692 The Automobile Handbook 

thrust from either side equally. The tire rim 
is mounted between the two conical felloe 
rims of the two wheel sections and is held in 
place by the rim bolts, thus making it secure. 
Since the tire rim is secured in place between 



Fig. 337 

Lindsay Twin Wire Wheel 


the two wheel rims by means of rim bolts it 
is evident that both wheel and tire rims will 
expand and contract together. By removing 
the rim bolts with a wrench and taking off 
the hub dust cap, the outer twin wheel can be 
dismounted, leaving the inner wheel intact, 
thereby releasing the tire. 

Another type of wire wheel is the Spranger, 



























The Automobile Handbook 693 

a view of which is shown in Figure 338. In 
this wheel there are 48 spokes interlaced in 
a simple cross system and equipped with a de¬ 
mountable rim, which like the demountable 



Fig. 338 

Spranger Wire Wheel 


rim on a wooden wheel, can be removed for 
the changing of the tire. The Spranger wheel 
itself is not demountable, and when installing 
these wheels on his car the owner obtains a 
complete new set of bearings, brake drums, and 


694 The Automobile Handbook 

hub caps. This type of wheel has recently 
come into extensive use on the Ford and Chev¬ 
rolet cars. In the construction of the Spranger 
wire wheel a special type of channel is used. 
This channel is of structural steel, and is li/ 2 
inches in width by % inch in depth, and into 
it the spokes are laced. The method of lock¬ 
ing the'rim to the wheel is as follows: each 
rim has six steel blocks securely riveted to it, 
which prevent the rim from rising or losing 
position, while at the same time there is no 
wedging action. 

In Figure 339 is presented a view of the 
Houk wire wheel, made by the Wire Wheel 
Corporation of America. 

Each wheel contains 72 steel wire spokes, 
each of which, before the wheel is assembled, 
is subjected to a test and must withstand a 
strain of 3,200 pounds. The spokes are ar¬ 
ranged in triple rows as will be seen by the 
illustration, the triple lacing thus providing a 
set of spokes to take up the strain from any 
direction. 

One end of each wire spoke is securely riv¬ 
eted to the rim, while the other end is secured 
to the hub in its proper location also by riv¬ 
eting. It is claimed that the interlacing of 
the spokes is of such a nature that three- 
fourths of them are continuously in use, sup¬ 
porting the load by suspension. In case of 
tire trouble, such as a puncture or blowout, 
the wheel can be removed in a few minutes 


The Automobile Handbook 


695 


by merely jacking up the car and unscrewing 
one nut. The wheel with the damaged tire 
can then be replaced by the extra wheel with a 
good tire. 

Mention has already been made* of the in¬ 
creased efficiency of the'wire wheel as a tire 



Fig. 339 

Houk Wire Wheel 


cooler, as compared with the wooden wheel. 
Another point in favor of wire wheels is the 
small area of spoke surface to be acted upon 
by the atmosphere in its resistance to the 
movement of the car. This resistance is always 
present, and the greater the area of the surface 
that is presented by a moving body for the 
atmospheric pressure to act upon, the greater 
will be the resistance tending to retard that 
movement. 












INDEX 


Page 

Acid, battery./. 7 

Accelerator . 7 

Accumulator . 8 

Acetylene gas . 317 

Adjustment, bearing. 86 

ignition. See name of system. 

Advance, automatic ignition.394, 438 

Air . 8 

cooling . 228 

resistance of. 8 

starter. 546 

Alcohol .10, 316 

cooling solutions . 239 

wood . 317 

Allis-Chalmers electrical equipment. 550 

Alloys . 14 

Alternating current . 16 

Aluminum .*... 16 

solder .*.v. 17 

Ammeter; construction of. 19 

use of . 18 

Ampere . 23 

-hour . 23 

Annealing . 23 

Anti-freeze mixtures. 239 

Armature, dynamo .24, 25 

Assembling . 511 

Atwater Kent ignition. 366 

wiring . 355 

Autolite electrical equipment. 556 

Automatic advance .394, 4S8 

Automobile . 26 

Axle, front.'. 27 

full-floating . 34 

rear . 33 

rear, internal gear. 33 

rear, worm driven. 44 

semi-floating . £3 

three-quarter floating .33, 37 








































The Automobile Handbook 


697 


B 


Ball bearings . 

Ball-socket joints. 

Band clutch. 

Battery connections . 

dry . 

storage . 

storage, care of . 

storage, charging 

storage, testing. 

Bearing, ball. 

ball, capacity of. 

ball, lubrication. 

metals . 

plain . 

roller.. 

Bendix drive. 

Benzine . 

Berline . 

Bijur electrical equipment 

Bodies . 

Bosch electrical equipment 

magneto. 

Brakes . 

lining for. 

use of . 

Brass . 

Brazing . 

Bronze . 


Page 

. 74 

. 47a 

. 209 

. 53 

. 51 

.55, 67 

.58, 68, 72 

. 65 

.65, 69 

. 74 

. 73 

. 79 

. 14 

. 82 

. 89 

. 93 

. 316 

. 102 

. 559 

. 96 

. 564 

408, 410, 414, 425, 464 

. 105 

. 109 

. 253 

. 15 

. 115 

. 15 


C 


Cabriolet . 104 

Camshaft, engine . 282 

Carbon deposit, removal of. 118 

Carburetion (see also Fuels, Fuel Mixtures and 
Fuel Feed). 

Carburetor, action of. 121 

alcohol . 13 

fuel flow in. 336 

Holly . 132 

inlet manifold. 284 

kerosene . 317 

Kingston . ' . 138 

Ray field .-. HO 









































698 The Automobile Handbook 

Page 

Schebler ... 147 

Stromberg . 152 

Zenith . 168 

Care and repair of cars . 511 

Cell, dry.. 51 

storage . 55 

Centrifugal pump . 234 

Chain, tire. 180 

Change speed gearing . 181 

Charging, storage battery . 65 

Chassis .207, 531 

Chauffeur . 207 

Clearance, plain bearing . 88 

Close coupled body. 100 

Clutch, action of. 207 

band . 209 

cone . 210 

disc . 214 

plate . 216 

trouble ... 217 

Coil, induction .351, 472 

Commutator, ignition . 361 

Compressed air starter. 546 

Compression ._. 221 

Condenser, ignition. 223 

Conductors, electrical and heat. 227 

Cone clutch . 210 

Connecticut ignition ..'. 376 

wiring. 350 

Cooling . 228 

anti-freeze mixtures for. 239 

water pump for . 234 

Coupe . 103 

Coupling, Oldham . 246 

Cut-out, electric. See name of system. 

muffler . 501 

Current, alternating and direct. 16 

secondary. 531 

v D 

Delco electrical equipment . 566 

ignition. 381 

Differential . 247 

bevel gear . 249 

spur gear. 252 












































The Automobile Handbook 


699 

' Page 

Disc clutch . 214 

valves .’ 664 

Distributor .’ 362 

Dixie magneto . 425 

Double ignition . 405 

Drive, Bendix . 93 

bevel gear . 33 

chain . 175 

friction . 182 

internal gear. 38 

planetary . 190 

shaft . 532 

sliding gear. 181 

worm gear. 44 

Driving, automobile . 256 

Dry battery . 51 

Dual ignition . 405 

Dynamometer . 267 

Dynamo armature .24, 25 

Dynamo, electric lighting. See name of system. 
Dyneto electrical equipment . 588 

E 

Eisemann magneto .430, 465 

Electricity . 267 

Electric gear shift . 493 

Electrolyte, battery. 7 

gravity of . 538 

Electromotive force . 267 

Engine, automobile (see also valves). 268 

compression in . 221 

eight and twelve cylinder. 301 

flywheel . 281 

four cycle . 289 

horsepower of . 342 

pistons . 277 

sliding sleeve . 296 

two cycle . 291 

Equalizer, brake . 112 

Exhaust, smoky . 312 

Expansion of mixture . 312 

F 

Fires, extinguishing. 338 

Fluxes, soldering . 528 










































700 The Automobile Handbook 

Page 

Flywheel, engine . 281 

Ford magneto . 441 

lubrication. 490 

transmission . 190 

Four cycle engine . 289 

Frames . 313 

Friction . 314 

transmission . 182 

Front dxle . 27 

Fuel (see also Alcohol, Gasoline, Kerosene). .130, 315 

alcohol as a. 10 

feed, vacuum. 327 

kerosene as a . 478 

mixture . 318 

G 

Gases, expansion of . 336 

Gasoline .316, 336 

air mixtures_ '. 318 

viscosity of . 336 

Gearing, change speed. 181 

horsepower transmitted by. 338 

planetary . 3-40 

Generators, electric lighting. See name of system. 

Gravity, specific. 538 

Gray and Davis electrical equipment. 591 

H 

Heat, unit of. 657 

Heinze magneto wiring. 466 

Holly carburetor . 132 

Horsepower . 341 

electrical . 345 

required . 8 

I 

Ignition (see also Magneto). 347 

Atwater Kent . 366 

condenser. 223 

Connecticut . 376 

control . 261 

Delco . 381 

distributor . 363 

double . 405 






































The Automobile Handbook 


701 

Page 

dual . 405 

Heinze . 466 

Kingston . 466 

magnetic type. 402 

Mea . 465 

Remy battery . 388 

Remy magneto .451, 468 

Simms magneto . 469 

single . 404 

Splitdorf .458, 471 

timing. 363 

* transformer coil. 405 

trouble . 364 

types of . 404 

Westinghouse . 392 

Induction coil .351, 472 

Inductor magneto.425, 448 

Inertia . 472 

Insulators .227, 472 

Internal gear rear axle . 38 

J 

Joints, ball and socket. 473 

knuckle. 474 

universal . 474 

K 

Kerosene . 317 

as a fuel . 478 

Kingston carburetor. 138 

magneto . 466 

Knight engine . 296 

Knocking . 479 

Knuckle, steering . 31 

L 

Lamps, electric . 481 

Landaulet. 102 

Lighting batteries. 103 

Lighting, electric (see starters). 546 

Limousine . 101 

Lubrication (see also Oil).482, 485, 490 

gear and clutch .• • • 400 

gear case and axle. 492 








































702 


The Automobile Handbook 


M 

Page 

Magnetic gear shift . 493 

transmission . 201 

Magnetism . 498 

Magneto, action of. 402 

Bosch .408, 421, 464 

care . 418 

Dixie . 425 

Eisemann .430, 465 

Ford . 441 

Heinze . 466 

inductor . 448 

Kingston . 466 

Mea.443, 465 

removal and replacement . 405 

Remy .448, 468 

Simms .453, 469 

Splitdorf .'...456, 471 

Manifold, inlet . 284 

Mea magneto .443, 465 

Metal, strength of. 645 

Mixture, fuel (see also fuel). 318 

Motor, automobile (see engine). 268 

spirit . 317 

Muffler, exhaust . 499 

N 

North East electrical equipment. 601 

O 

Oil, (see also Lubrication). 482 

tests of .485, 488 

Oldham coupling . 246 

Overhauling. 511 

Owen magnetic transmission. 201 

Oxy-acetylene welding . 680 

P 

Packing, materials for . 502 

Picric afcid. 503 

Piston, engine.’ 274 




































The Automobile Handbook 


703 


Plain bearings. 82 

Planetary gearing .’ 340 

transmission .’ ig7 

Plate clutch.’ 216 

Plugs, spark . 7 . 533 , 537 

Polarity . 503 

Porcelain . 504 

Pounding, causes of . 504 

Preignition . 532 

causes of . 505 

Pump, water . 234 


R 


Radiator—see Cooling. 

Rayfield carburetor .. 

Rear axle. 

Regulator, current, Allis-Chalmers 

Bijur . 

Bosch . 

Delco. 

Gray and Davis . 

North East . 

Remy . 

Rushmore. 

Simms-Huff . 

Splitdorf-Apelco. 

U. S. L. 

Wagner. 

Westinghouse . 

Remy electrical equipment. 

ignition . 

magneto. 

wiring. 

Repair work . 

Resistance, electrical . 

Rheostat. 

Rim, wheel . 

Rings, piston . 

Roadster .. 

Roller bearings. 

Rotary valves. 

Runabout . 

Running gear. 

Rushmore electrical equipment ... 


. 140 

. 33 

. 552 

. 559 

. 565 

,567, 576, 581, 585 

.592, 596 

. 601 

.604, 607 

. 612 

. 613 

. 615 

. 621 

. 624 

.627, 629 

. 602 

388 

448,’ 451,’ 46*7, 468 

. 350 

. 511 

. 227 

. 531 

. 689 

. 280 

. 101 

. 89 


662 

101 

531 

809 


\ 











































704 


The Automobile Handbook 


S 

Page 

Sedan . 102 

Shop work. 511 

Simms-Huff electrical equipment. 612 

Simms magneto .453, 469 

Single ignition. 404 

Skidding. 260 

Sleeve valves. 660 

Sliding gear transmission. 192 

sleeve engine . 296 

Solder, aluminum. 17 

Soldering .527, 532 

Spark plugs . 533 

Specific gravity . 538 

Splitdorf-Apelco electrical equipment. 614 

Splitdorf magneto .456, 458, 470, 471 

Springs, automobile . 539 

care of . 543 

dimensions of. 541 

eye and clip sizes. 544 

leaf points of . 545 

testing of. 542 

Sprockets . 177 

Starter, air. 546 

engine . 546 

Allis-Chalmers . 550 

Autolite . 556 

Bijur . 559 

Bosch. 564 

Delco . 566 

Dyneto . 588 

Gray and Davis. 591 

North East. 601 

Remy. 602 

Rushmore . 609 

Simms-Huff . 612 

Splitdorf-Apelco . 614 

U. S. L. 618 

Wagner. 622 

Westinghouse . 627 

Starting motor drive, Bendix. 93 

Steel . 637 

Steering gear . 638 

knuckle . 31 

Storage battery. 55 , 67 














































The Automobile Handbook 705 

Page 

Strength of metal . 645 

Stromberg carburetor . 152 

T 

Tar benzol . 316 

Thermo-syphon cooling . 232 

Threads, screw. 647 

Timer, ignition . 361 

Timing of valves .668 

of ignition (see also name of System). 363 

Tire care and repair. 647 

vulcanizing . 651 

Tools, automobile . 513 

Torpedo body . 100 

Torsion rod . 654 

Touring car. * . 100 

Town car . 103 

Traction of driving wheels . 654 

Transformer coil ignition. 405 

Transmission (see also Change Speed). 181 

Ford . 190 

friction . 182 

gearless . 200 

gearing . 338 

magnetic .. 201 

planetary . 187 

sliding gear. 192 

Trouble, clutch. 217 

cooling.236, 245 

ignition .:. 364 

knocking. 479 

pounding . 504 

preignition. 505 

starting and lighting. 554 

steering gear . 642 

storage battery. 59 

Two cycle engine. 291 

U 

Unit of heat . 657 

Universal joint. 474 

U. S. L. electrical equipment. 618 

V 

Vacuum fuel feed. 227 








































706 The Automobile Handbook 

Page 

Valves, automobile engine . 658 

clearance of. 665 

disc. 664 

grinding of . 675 

lead of . 668 

location of . 658 

rotary . 662 

sleeve . v .296, 660 

tappet adjustment of . \ . 665 

timing of . 668 

Vulcanizing . 651 

W 

Wagner electrical equipment. 622 

Water cooling. 232 

Watt-hour . 680 

Welding, oxy-acetylene . 680 

Westinghouse electrical equipment. 627 

ignition. 392 

Wheels, wood . 682 

wire . 690 

Wiring, Allis-Chalmers . 553 

Atwater Kent . 355 

Bijur.561, 562 

Bosch .410, 414, 425, 464 

Connecticut . 350 

Delco .567, 568, 577 

Eisemann . 465 

Gray & Davis.593, 597 

Heinze. 466 

Kingston . 466 

Mea . . . 465 

Remy .350, 605 

Remy magneto .451, 452, 467, 468 

Simms magneto . 469 

Splitdorf-Apelco . 616 

Splitdorf magneto.458, 459, 470, 471 

U. S. L.620, 623 

Westinghouse .630, 631, 635 

Westinghouse ignition. 399 

Worn driven rear axle. 44 

Z 

Zenith carburetor . 168 




























































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